Wireless degradation data generator for use with a therapeutic scaffold and methods for use therewith

ABSTRACT

A degradation data generator is used with a scaffold for delivery within a patient. The degradation data generator includes a driving circuit electrically coupled to drive an impedance of the scaffold. A detection circuit generates degradation data based on the impedance of the scaffold or other properties such as RF or lightwave transmission, conductance or absorption. The degradation data indicates an amount of biodegradation of the scaffold. A wireless transmitter is coupled to transmit the degradation data to a wireless degradation data receiver, while the scaffold is within the patient.

CROSS REFERENCE TO RELATED PATENTS

The present U.S. Utility Patent Application claims priority pursuant to35 U.S.C. § 120 as a continuation of Ser. No. 15/616,432, entitled“WIRELESS DEGRADATION DATA GENERATOR FOR USE WITH A THERAPEUTIC SCAFFOLDAND METHODS FOR USE THEREWITH”, filed Jun. 7, 2017, which claimspriority pursuant to 35 U.S.C. § 121 as a divisional of U.S. Utilityapplication Ser. No. 14/159,157, entitled “WIRELESS DEGRADATION DATAGENERATOR FOR USE WITH A THERAPEUTIC SCAFFOLD AND METHODS FOR USETHEREWITH”, filed Jan. 20, 2014, now issued as U.S. Pat. No. 9,700,244on Jul. 11, 2017, which claims priority pursuant to 35 U.S.C. § 119(e)to U.S. Provisional Application No. 61/892,901, entitled “WIRELESSDEGRADATION DATA GENERATOR FOR USE WITH A THERAPEUTIC SCAFFOLD ANDMETHODS FOR USE THEREWITH”, filed Oct. 18, 2013; and U.S. ProvisionalApplication No. 61/885,886, entitled “SHAPE MEMORY CATHETERIZATIONDEVICE WITH ELECTRICAL TRANSFORMATION FEEDBACK AND METHODS FOR USETHEREWITH”, filed Oct. 2, 2013, all of which are hereby incorporatedherein by reference in their entirety and made part of the present U.S.Utility Patent Application for all purposes.

U.S. Utility patent application Ser. No. 14/159,157 claims prioritypursuant to 35 U.S.C. § 120 as a continuation-in-part of U.S. Utilityapplication Ser. No. 13/956,501, entitled “SYSTEM FOR DEPLOYING ARESISTIVE SHAPE MEMORY CATHETERIZATION DEVICE AND METHODS FOR USETHEREWITH”, filed Aug. 1, 2013, now issued as U.S. Pat. No. 10,463,516on Nov. 5, 2019, which claims priority pursuant to 35 U.S.C. § 119(e) toU.S. Provisional Application No. 61/754,473, entitled “SHAPE MEMORYCATHETERIZATION DEVICE WITH ELECTRICAL TRANSFORMATION FEEDBACK ANDMETHODS FOR USE THEREWITH”, filed Jan. 18, 2013, all of which are herebyincorporated herein by reference in their entirety and made part of thepresent U.S. Utility Patent Application for all purposes.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

NOT APPLICABLE

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

NOT APPLICABLE

BACKGROUND OF THE INVENTION Technical Field of the Invention

This invention relates generally to medical devices that prepare andintravenously insert scaffolds in a patient to deliver therapeuticmaterials.

Description of Related Art

A wide range of medical treatments can be performed with a catheter thatis intravenously inserted in a patient. Such catheterizations havereduced invasiveness compared with conventional treatments leading tolower risk to the patient, faster healing times, etc. Shape memorydevices that change shape based on temperature have been used in suchcatheterizations. These devices can be lightweight and biocompatible.

The disadvantages of conventional approaches will be evident to oneskilled in the art when presented the disclosure that follows.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

FIG. 1 is a schematic block diagram of an embodiment of a system fordeploying a shape memory catheterization device 98 in accordance withthe present invention;

FIG. 2 is a schematic block diagram of an embodiment of a system fordeploying a shape memory catheterization device 98 in accordance withthe present invention;

FIG. 3 is a graphical representation of a temperature profile of inaccordance with an embodiment the present invention;

FIG. 4 is a flow diagram of an embodiment of a method in accordance withthe present invention;

FIG. 5 is a schematic block diagram of an embodiment of a driver circuit112 and detection circuit 114 in accordance with the present invention;

FIG. 6 is a graphical representation of a resistance profile inaccordance with an embodiment the present invention;

FIG. 7 is a schematic block diagram of an embodiment of a driver circuit112 and detection circuit 114 in accordance with the present invention;

FIG. 8 is a graphical representation of a capacitance profile inaccordance with an embodiment the present invention;

FIG. 9 is a schematic block diagram of an embodiment of a driver circuit112 and detection circuit 114 in accordance with the present invention;

FIG. 10 is a graphical representation of inductance profile inaccordance with an embodiment the present invention;

FIG. 11 is a schematic block diagram of an embodiment of a drivercircuit 112 and detection circuit 114 in accordance with the presentinvention;

FIG. 12 is a graphical representation of a strain profile in accordancewith an embodiment the present invention;

FIG. 13 is a pictorial representation of the shape transformation of ashape memory member of in accordance with an embodiment the presentinvention;

FIG. 14 is a pictorial representation of the transformation of a shapememory member of in accordance with an embodiment the present invention;

FIG. 15 is a pictorial representation of the transformation of a shapememory member of in accordance with an embodiment the present invention;

FIG. 16 is a pictorial representation of the transformation of a shapememory member of in accordance with an embodiment the present invention;

FIG. 17 is a pictorial representation of the transformation of a shapememory member of in accordance with an embodiment the present invention;

FIG. 18 is a pictorial representation of the transformation of a shapememory member of in accordance with an embodiment the present invention;

FIG. 19 is a pictorial representation of the transformation of a shapememory member of in accordance with an embodiment the present invention;

FIG. 20 is a pictorial representation of the transformation of a shapememory member of in accordance with an embodiment the present invention;

FIG. 21 is a pictorial representation of a shape memory member andcatheter in accordance with an embodiment the present invention;

FIG. 22 is a pictorial representation of a shape memory member andcatheter in accordance with an embodiment the present invention;

FIG. 23 is a pictorial representation of a shape memory member andcatheter in accordance with an embodiment the present invention;

FIG. 24 is a flowchart representation of an embodiment of a method inaccordance with the present invention;

FIG. 25 is a flowchart representation of an embodiment of a method inaccordance with the present invention;

FIG. 26 is a flowchart representation of an embodiment of a method inaccordance with the present invention;

FIG. 27 is a flowchart representation of an embodiment of a method inaccordance with the present invention;

FIG. 28 is a flowchart representation of an embodiment of a method inaccordance with the present invention;

FIG. 29 is a flowchart representation of an embodiment of a method inaccordance with the present invention;

FIG. 30 is a flowchart representation of an embodiment of a method inaccordance with the present invention;

FIG. 31 is a schematic block diagram of an embodiment of a system formonitoring a scaffold 200 in accordance with the present invention;

FIG. 32 is a schematic block diagram of an embodiment of a system formonitoring a scaffold 200 in accordance with the present invention;

FIG. 33 is a schematic block diagram of an embodiment of a system formonitoring a scaffold 200 in accordance with the present invention;

FIG. 34 is a schematic block diagram of an embodiment of a system formonitoring a scaffold 200 in accordance with the present invention;

FIG. 35 is a graphical representation of a loading profile in accordancewith an embodiment the present invention;

FIG. 36 is a graphical representation of an unloading profile inaccordance with an embodiment the present invention;

FIG. 37 is a schematic block diagram of an embodiment of a loading datagenerator in accordance with the present invention;

FIG. 38 is a schematic block diagram of an embodiment of a loading datagenerator in accordance with the present invention;

FIG. 39 is a schematic block diagram of an embodiment of a loading datagenerator in accordance with the present invention;

FIG. 40 is a pictorial diagram of a scaffold and catheter in accordancewith an embodiment of the present invention;

FIG. 41 is a pictorial diagram of a scaffold and catheter in accordancewith an embodiment of the present invention;

FIG. 42 is a pictorial diagram of a scaffold and catheter in accordancewith an embodiment of the present invention;

FIG. 43 is a flowchart representation of an embodiment of a method inaccordance with the present invention;

FIG. 44 is a flowchart representation of an embodiment of a method inaccordance with the present invention;

FIG. 45 is a flowchart representation of an embodiment of a method inaccordance with the present invention;

FIG. 46 is a schematic block diagram of an embodiment of driver circuitand detection circuit in accordance with the present invention;

FIG. 47 is a schematic block diagram of an embodiment of driver circuitand detection circuit in accordance with the present invention;

FIG. 48 is a schematic block diagram of an embodiment of a system formonitoring a scaffold in accordance with the present invention;

FIG. 49 is a schematic block diagram of an embodiment of a loading datagenerator in accordance with the present invention;

FIG. 50 is a pictorial diagram of a scaffold in accordance with anembodiment of the present invention;

FIG. 51 is a graphical representation of an unloading profile inaccordance with an embodiment the present invention;

FIG. 52 is a schematic block diagram of an embodiment of a system formonitoring a scaffold in accordance with the present invention;

FIG. 53 is a schematic block diagram of an embodiment of a degradationdata generator in accordance with the present invention;

FIG. 54 is a pictorial diagram of a scaffold in accordance with anembodiment of the present invention;

FIG. 55 is a graphical representation of degradation profiles inaccordance with an embodiment the present invention;

FIG. 56 is a flowchart representation of an embodiment of a method inaccordance with the present invention;

FIG. 57 is a flowchart representation of an embodiment of a method inaccordance with the present invention;

FIG. 58 is a flowchart representation of an embodiment of a method inaccordance with the present invention; and

FIG. 59 is a flowchart representation of an embodiment of a method inaccordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a schematic block diagram of an embodiment of a system fordeploying a shape memory catheterization device 98 in accordance withthe present invention. In particular, a shape memory catheterizationdevice 98 includes a catheter having a delivery rod 150 for use inconjunction with a catheterization procedure involving the insertion ofthe shape memory catheterization device 98 into a patient. Examples ofsuch catheterization procedures include the insertion of an endovascularstent as part of an angioplasty or treatment of an aneurism or theintravenous deployment of another medical device, an intravenous drugdeployment or the administration of anesthetic medication into theepidural space, the subarachnoid space, or around a major nerve bundlesuch as the brachial plexus, the administration of anesthetic medicationinto the epidural space, the subarachnoid space, or around a major nervebundle such as the brachial plexus, an in vitro fertilization or othermedical treatment, a urinary catheterization, treatment of an abdominalabscess, a balloon septostomy, balloon sinuplasty, catheter ablation, anin vitro fertilization or other medical treatment.

The shape memory catheterization device 98 includes a shape memorymember 100 having a transition temperature that is higher than a normalbody temperature of the patient. When heat is applied by a heat source104 the shape memory member 100 of shape memory catheterization device98 is heated above the transition temperature causes the shape memorymember 100 to undergo a shape transformation from a catheterizationshape into a transformed shape that is useful in the particulartreatment. The heat source 104 can be an infrared emitter, laser orother light source, a heating coil or other electrical heating source, amicrowave source or other electromagnetic source, a radiation source orother heat source. While shown separately from the shape memorycatheterization device 98, the heat source 104 can be integrated intothe shape memory catheterization device 98.

A transformation data generator 102 includes a circuit driver 112 fordriving a circuit that includes at least one electrical element of theshape memory member 100 via a signal line included in the delivery rodand a plurality of electrodes that couple to the shape memory device100. The transformation data generator 102 also includes a detectioncircuit 114 for generating transformation data 106 based on feedbackgenerated by the detection circuit 114. The transformation data 106indicates a shape transformation of the shape memory member 100 of theshape memory catheterization 98 device from the catheterization shape tothe transformed shape. In an embodiment of the present invention thetransformation data 106 can be displayed or otherwise used to providevisual, audible or tactile feedback to the users of shape memorycatheterization device 98 that the shape memory member 100 has reachedits transformation shape.

Further examples including numerous optional functions and features ofshape memory catheterization device 98 are discussed in conjunction withFIGS. 2-30 that follow.

FIG. 2 is a schematic block diagram of an embodiment of a system fordeploying a shape memory catheterization device 98 in accordance withthe present invention. In particular, a system is shown that includesmany common elements of those described in conjunction with FIG. 1 thatare referred to by common reference numerals. In addition, a heatingcontrol generator 110 is included that generates a control signal 108for controlling the heat source 104 based on the transformation data106. In operation, the heating control generator generates the controlsignal 108 to discontinue the heating of the shape memorycatheterization device 98 when the transformation data 106 indicates theshape transformation of the shape memory member 100 from thecatheterization shape to the transformed shape.

In an example of operation, the shape memory member 100 is a shapememory polymer, alloy or other device with a transition temperature thatis slightly above the body temperature of the patient. The shape memorymember 100 is heated above the transition temperature to effectuate theshape transformation of the shape memory member as part of thetreatment. Overheating of blood or tissue can cause undesirable bloodclotting during a treatment or other harmful effects. Discontinuingheating by heat source 104 after the shape transformation has occurredcan avoid overheating the patient's tissue, blood and other body fluidsduring the procedure and allows the users of shape memorycatheterization device to provide only as much heat as is reasonablynecessary to effectuate the shape transformation.

Heating control generator 110 can be implemented using a processingdevice such as shared processing device, individual processing devices,or a plurality of processing devices and may further include memory.Such a processing device may be a microprocessor, micro-controller,digital signal processor, microcomputer, central processing unit, fieldprogrammable gate array, programmable logic device, state machine, logiccircuitry, digital circuitry, and/or any device that manipulates signalsbased on operational instructions. The memory may be a single memorydevice or a plurality of memory devices. Such a memory device may be aread-only memory, random access memory, volatile memory, non-volatilememory, static memory, dynamic memory, flash memory, and/or any devicethat stores digital information. Note that when the processing deviceimplements one or more of its functions via a state machine, digitalcircuitry, and/or logic circuitry, the memory storing the correspondingoperational instructions is embedded with the circuitry comprising thestate machine, digital circuitry, and/or logic circuitry.

FIG. 3 is a graphical representation of a temperature profile inaccordance with an embodiment of the present invention. In particular, atemperature profile is presented of a shape memory member, such as shapememory member 100. The shape memory member can be a shape memory polymersuch as a cold hibernated elastic memory (CHEM) polymer or other shapememory polymer, shape memory alloy or other shape memory device. Asshown, the elastic modulus, E, of the shape memory member 100 changesbased on whether the temperature, T, of the shape memory member is aboveor below a transition temperature, T_(t). For the range of temperaturesT<T_(t), the elastic modulus is high and the shape memory member isrigid and holds a particular shape. For the range of temperaturesT>T_(t), the elastic modulus is low and the shape memory member isflexible. Consider the example where the shape memory member 100 is ashape memory polymer that has a transition temperature, T_(t), thatcorresponds to a glass transition. For the range of temperaturesT<T_(t), the shape memory member is in a glassy state and is rigid. Forthe range of temperatures T>T_(t), the shape memory member is in arubbery state and the shape memory member is flexible. This property ofthe shape memory member can be used to create a heat induced shapetransformation as described in conjunction with FIG. 4 .

FIG. 4 is a flow diagram of an embodiment of a method in accordance withthe present invention. In step 120, a shape memory member, such as shapememory member 100 of shape memory catheterization device 98, is heatedabove its transition temperature and enters a flexible state. In step122, the shape memory member is deformed from an original shape into itscatheterization shape. In step 124, the shape memory member is cooledwhile constrained to its catheterization shape, and becomes rigid,allowing it to retain its deformed catheterization shape when theconstraint is removed. In step 126, the shape memory member is heatedduring catheterization for deployment as part of the catheterizationtreatment. When the shape memory member reenters the rubbery state, theshape memory member undergoes a shape transformation back to itsoriginal shape.

As shown in step 128, the shape transformation of the shape memorymember 100 is detected based on transformation data, such astransformation data 106 generated by the transformation data generator104. As discussed in conjunction with FIG. 1 , the transformation data106 can be displayed or otherwise used to provide visual, audible ortactile feedback to the users of shape memory catheterization device 98that the shape memory member 100 has reached its transformation shape.As discussed in conjunction with FIG. 2 , the transformation data can beused by a heating control generator to generate the control signal 108to discontinue the heating of the shape memory member 100 when thetransformation data indicates the shape transformation of the shapememory member has gone from the catheterization shape to the transformedshape. If the shape memory member 100 is a stent or other device that isto remain in the body, the cooling of the shape memory member back tothe body temperature of the patient causes the shape memory member toreturn to its rigid state to hold the transformed shape.

In an embodiment, prior to step 120 a shape memory member can be formedinto a desired deployment shape, such as via laser cutting or othercutting, by molding or by other formation technique. Prior to step 126,the shape memory member can be delivered via the catheter.

FIG. 5 is a schematic block diagram of an embodiment of a driver circuit112 and detection circuit 114 in accordance with the present invention.In this embodiment, the shape memory member 100 includes a resistiveelement that has a resistance R_(sm) that changes in response to theshape transformation of the shape memory member. For example, the shapememory member 100 can be a shape memory polymer with electricallyresistive properties, that is surface doped with a conductive orpartially conductive compound, or that is doped to saturation with aconductive or partially conductive compound. In a further example theshape memory member can be formed of a shape memory polymer to include aflexible resistive member such as a metallic foil element adhered ordeposited on the surface of the shape memory member, a flexible foil orcoil insert, a resistive foam member or insert or other resistivemember. In addition, the shape memory member can be formed of a shapememory alloy that is electrically conductive with a resistance thatchanges in response to the shape transformation of the shape memorymember 100.

The driver circuit includes a power source, such as the voltage sourceshown, that drives the detection circuit 114 and a wheatstone bridgeformed with the resistive element of the shape memory member 100 and aplurality of fixed resistors. The voltage detector 105 monitors thechange in resistance of the resistive element of shape memory member 100and generates the transformation data 104, for example, when the changein resistance R_(sm) indicates that the shape transformation hasoccurred.

In an embodiment, the voltage detector 105 generates the transformationdata 106 to indicate the shape transformation of the shape memory memberfrom the catheterization shape to the transformed shape when theresistance R_(sm) of the resistive element compares favorably to atransformation threshold. In particular, the transformation data 106 caninclude a data flag having a first value that indicates thecatheterization shape and a second value that indicates the transformedshape. The transition of the transformation data 106 from the firstvalue to the second value can indicate that the transformation hasoccurred.

FIG. 6 is a graphical representation of a resistance profile of inaccordance with an embodiment the present invention. An exampleresistance profile of a resistive element of shape memory member 100 isshown. As the shape memory member is heated in conjunction with thedeployment of the shape memory catheterization device, the resistance,R_(sm), changes with time. In particular, the resistance R_(sm) changesin response to the shape transformation of the shape memory member 100caused by the heating of the shape memory catheterization device.

As discussed in conjunction with FIG. 5 , the voltage detector 105generates the transformation data 106 to indicate the shapetransformation of the shape memory member 100 from the catheterizationshape to the transformed shape when the resistance R_(sm) of theresistive element compares favorably to a transformation threshold. Inthe example shown, the transformation over time of the shape memorymember causes the resistance R_(sm) to increase. At a time, T₁, theresistance R_(sm) reaches a transition threshold, R_(tt), and stabilizesindicating the shape transformation is complete. In this example thevoltage detector can include a comparator that generates thetransformation data 106 when the R_(sm) meets or exceeds the transitionthreshold, R_(tt).

While the transformation over time of the shape memory member causes theresistance R_(sm) to increase in the example shown, in other examples,the resistance may decrease depending on the nature of the original andcatheterization shape of the shape memory member and/or the nature,position and orientation of the resistive element or elements includedin the shape memory member 100, etc. Further, while the voltage detectorhas been described in terms of comparing the resistance R_(sm) to atransition threshold, R_(tt). other metrics such as the stabilization ofthe resistance R_(sm) can likewise be employed.

Further, while the embodiments above contemplate a shape memory device100 with a single resistive element, multiple resistive elements can bedriven and monitored by transformation data generator 102. For example,resistive elements can be placed at multiple points, on multiple axes oftransformation or otherwise on multiple portions of a shape memorymember 100. In this configuration, transformation data 106 can begenerated to indicate the transform shape when all of the resistiveelements indicate a transformation has taken place.

FIG. 7 is a schematic block diagram of an embodiment of a driver circuit112 and detection circuit 114 in accordance with the present invention.In this embodiment, the shape memory member 100 includes a capacitiveelement that has a capacitance C_(sm) that changes in response to theshape transformation of the shape memory member. For example, the shapememory member 100 can be a shape memory polymer with capacitiveproperties, that is includes a plurality of plates that are surfacedoped with a conductive or partially conductive compound, a metallicfoil element adhered or deposited on the surface of the shape memorymember or a conductive foam or other conductive element that forms theplates. The shape memory polymer further includes an electrolytic,dielectric or insulator made of a shape memory polymer that is disposedbetween the plurality of plates. In addition, the shape memory membercan be formed of a shape memory alloy that is electrically conductivewith a capacitance such as a parasitic capacitance that changes inresponse to the shape transformation of the shape memory member 100.

The driver circuit 112 includes a power source, such as the voltagesource shown, that drives the detection circuit 114 via an alternatingcurrent such as the step waveform generator that is shown. The drivercircuit further includes a detection resistance R_(d) that forms an RCcircuit with the capacitive element of the shape memory member 100. Thevoltage detector 105 monitors the change in capacitance of thecapacitive element of shape memory member 100 based on monitoring thetime of charging and/or discharging of the capacitive element. Thevoltage detector generates the transformation data 104, for example,when the change in capacitance C_(sm) indicates that the shapetransformation has occurred.

In an embodiment, the voltage detector 105 generates the transformationdata 106 to indicate the shape transformation of the shape memory memberfrom the catheterization shape to the transformed shape when thecapacitance C_(sm) of the capacitive element compares favorably to atransformation threshold. In particular, the transformation data 106 caninclude a data flag having a first value that indicates thecatheterization shape and a second value that indicates the transformedshape. The transition of the transformation data 106 from the firstvalue to the second value can indicate that the transformation hasoccurred.

FIG. 8 is a graphical representation of a capacitance profile of inaccordance with an embodiment the present invention. An examplecapacitance profile of a capacitive element of shape memory member 100is shown. As the shape memory member 100 is heated in conjunction withthe deployment of the shape memory catheterization device, thecapacitance, C_(sm), changes with time. In particular, the capacitanceC_(sm) changes in response to the shape transformation of the shapememory member caused by the heating of the shape memory catheterizationdevice.

As discussed in conjunction with FIG. 7 , the voltage detector 105generates the transformation data 106 to indicate the shapetransformation of the shape memory member from the catheterization shapeto the transformed shape when the capacitance C_(sm) of the capacitiveelement compares favorably to a transformation threshold. In the exampleshown, the transformation over time of the shape memory member causesthe capacitance C_(sm) to increase. At a time, T₁, the capacitanceC_(sm) reaches a transition threshold, C_(tt), and stabilizes indicatingthe shape transformation is complete. In this example the voltagedetector can include a comparator that generates the transformation data106 when the C_(sm) meets or exceeds the transition threshold, C_(tt).

While the transformation over time of the shape memory member causes thecapacitance C_(sm) to increase in the example shown, in other examples,the capacitance may decrease depending on the nature of the original andcatheterization shape of the shape memory member and/or the nature,position and orientation of the capacitive element or elements includedin the shape memory member, etc. Further, while the voltage detector hasbeen described in terms of comparing the capacitance C_(sm) to atransition threshold, C_(tt). other metrics such as the stabilization ofthe capacitance C_(sm) can likewise be employed.

Further, while the embodiments above contemplate a shape memory devicewith a single capacitive element, multiple capacitive elements can bedriven and monitored by transformation data generator 102. For example,capacitive elements can be placed at multiple points, on multiple axesof transformation or otherwise on multiple portions of a shape memorymember 100. In this configuration, transformation data 106 can begenerated to indicate the transformation shape when all of thecapacitive elements indicate a transformation has taken place.

FIG. 9 is a schematic block diagram of an embodiment of a driver circuit112 and detection circuit 114 in accordance with the present invention.In this embodiment, the shape memory member 100 includes an inductiveelement that has an inductance L_(sm) changes in response to the shapetransformation of the shape memory member. For example, the shape memorymember can be a shape memory polymer with electrically inductiveproperties, that is surface doped with a conductive or partiallyconductive compound, or that is doped to saturation with a conductive orpartially conductive compound. In a further example the shape memorymember can be formed of a shape memory polymer to include a flexibleinductive member such as a metallic foil element adhered or deposited onthe surface of the shape memory member, a flexible foil or coil insert,a conductive foam member or insert or other inductive member. Inaddition, the shape memory member can be formed of a shape memory alloythat is electrically conductive with an inductance that changes inresponse to the shape transformation of the shape memory member 100.

The driver circuit 112 includes a power source, such as the voltagesource shown, that drives the detection circuit 114 via an alternatingcurrent such as the step waveform generator that is shown. The drivercircuit further includes a detection resistance R_(d) that forms an RLcircuit with the inductive element of the shape memory member 100. Thevoltage detector 105 monitors the change in inductance of the inductiveelement of shape memory member 100 based on monitoring the time ofcharging and/or discharging of the inductive element. The voltagedetector generates the transformation data 104, for example, when thechange in inductance L_(sm) indicates that the shape transformation hasoccurred.

In an embodiment, the voltage detector 105 generates the transformationdata 106 to indicate the shape transformation of the shape memory memberfrom the catheterization shape to the transformed shape when theinductance L_(sm) of the inductive element compares favorably to atransformation threshold. In particular, the transformation data 106 caninclude a data flag having a first value that indicates thecatheterization shape and a second value that indicates the transformedshape. The transition of the transformation data from the first value tothe second value can indicate that the transformation has occurred.

FIG. 10 is a graphical representation of an inductance profile of inaccordance with an embodiment the present invention. An exampleinductance profile of an inductive element of shape memory member 100 isshown. As the shape memory member is heated in conjunction with thedeployment of the shape memory catheterization device, the inductance,L_(sm), changes with time. In particular, the inductance L_(sm) changesin response to the shape transformation of the shape memory membercaused by the heating of the shape memory catheterization device.

As discussed in conjunction with FIG. 9 , the voltage detector 105generates the transformation data 106 to indicate the shapetransformation of the shape memory member from the catheterization shapeto the transformed shape when the inductance L_(sm) the inductiveelement compares favorably to a transformation threshold. In the exampleshown, the transformation over time of the shape memory member causesthe inductance L_(sm) to increase. At a time, T₁, the inductance L_(sm)reaches a transition threshold, L_(tt), and stabilizes indicating theshape transformation is complete. In this example the voltage detectorcan include a comparator that generates the transformation data 106 whenthe inductance L_(sm) meets or exceeds the transition threshold, L_(tt).

While the transformation over time of the shape memory member causes theinductance L_(sm) to increase in the example shown, in other examples,the inductance may decrease depending on the nature of the original andcatheterization shape of the shape memory member and/or the nature,position and orientation of the inductive element or elements includedin the shape memory member, etc. Further, while the voltage detector hasbeen described in terms of comparing the inductance L_(sm) to atransition threshold, L_(tt). other metrics such as the stabilization ofthe inductance L_(sm) can likewise be employed.

Further, while the embodiments above contemplate a shape memory devicewith a single inductive element, multiple inductive elements can bedriven and monitored by transformation data generator 102. For exampleinductive elements can be placed at multiple points, on multiple axes oftransformation or otherwise on multiple portions of a shape memorymember 100. In this configuration, transformation data 106 can begenerated to indicate the transform shape when all of the inductiveelements indicate a transformation has taken place.

FIG. 11 is a schematic block diagram of an embodiment of a drivercircuit 112 and detection circuit 114 in accordance with the presentinvention. In this embodiment, the shape memory member 100 includes astrain gage that has a resistance R_(sm) that changes in response tostrain on the shape memory member 100. For example, the shape memorymember 100 can be a shape memory polymer or other shape memory memberwith a strain gage adhered or deposited on the surface of the shapememory member. In particular, strain and corresponding resistance R_(sm)change with the shape transformation of the shape memory member 100.

The driver circuit includes a power source, such as the voltage sourceshown, that drives the detection circuit 114, and a wheatstone bridgeformed with the resistive element R_(sm) of the strain gage of shapememory member 100 and a plurality of fixed resistors. The voltagedetector 105 monitors the change in strain of the strain gage bymonitoring the resistance of strain gage and generates thetransformation data 104, for example, when the change in resistanceR_(sm) indicates that the shape transformation has occurred.

In an embodiment, the voltage detector 105 generates the transformationdata 106 to indicate the shape transformation of the shape memory memberfrom the catheterization shape to the transformed shape when theresistance R_(sm) (corresponding to the strain of the strain gage)compares favorably to a transformation threshold. In particular, thetransformation data 106 can include a data flag having a first valuethat indicates the catheterization shape and a second value thatindicates the transformed shape. The transition of the transformationdata from the first value to the second value can indicate that thetransformation has occurred.

FIG. 12 is a graphical representation of a strain profile of inaccordance with an embodiment the present invention. An example strainprofile of a strain gage of shape memory member 100 is shown. As theshape memory member is heated in conjunction with the deployment of theshape memory catheterization device, the strain, S_(sm), changes withtime. In particular, the strain S_(sm) changes in response to the shapetransformation of the shape memory member caused by the heating of theshape memory catheterization device.

As discussed in conjunction with FIG. 11 , the voltage detector 105generates the transformation data 106 to indicate the shapetransformation of the shape memory member from the catheterization shapeto the transformed shape when the resistance R_(sm) corresponding to thestrain S_(sm) of the strain gage compares favorably to a transformationthreshold. In the example shown, the transformation over time of theshape memory member causes the strain S_(sm) to increase. At a time, T₁,the strain S_(sm) reaches a transition threshold, S_(tt), and stabilizesindicating the shape transformation is complete. In this example thevoltage detector can include a comparator that generates thetransformation data 106 when the S_(sm) meets or exceeds the transitionthreshold, S_(tt).

While the transformation over time of the shape memory member causes thestrain S_(sm) to increase in the example shown, in other examples, thestrain may decrease depending on the nature of the original andcatheterization shape of the shape memory member and/or the nature,position and orientation of the strain gage or gages included in theshape memory member, etc. Further, while the voltage detector has beendescribed in terms of comparing the strain S_(sm) to a transitionthreshold, S_(tt). other metrics such as the stabilization of the strainS_(sm) can likewise be employed.

Further, while the embodiments above contemplate a shape memory devicewith a single strain gage, multiple strain gages can be driven andmonitored by transformation data generator 102. For example, straingages can be placed at multiple points, on multiple axes oftransformation or otherwise on multiple portions of a shape memorymember 100. In this configuration, transformation data 106 can begenerated to indicate the transform shape when all of the strain gagesindicate a transformation has taken place.

FIG. 13 is a pictorial representation of the shape transformation of ashape memory member of in accordance with an embodiment the presentinvention. In particular, a shape memory member 100 is presented as acylinder. Examples of such shape memory members include a cylindricaltube constructed with shape memory polymer for grafting a vein or arteryto treat an aneurism or a cylindrical tube constructed with shape memorypolymer or cylindrical mesh constructed with either a shape memorypolymer or shape memory alloy for supporting a vein or artery afterremoving a blockage. In the configuration shown, the shape memory member100 is fitted on a delivery rod to be delivered through a delivery rod150 (a portion of which is shown schematically) and is deformed from anoriginal shape 120 into a catheterization shape 122 with reduceddiameter via crimping. When the shape memory member 100 is heated duringdeployment, it transforms into the transformed shape 124 that issubstantially the original shape 120, subject to, for example, physicalconformity to the tissue, such as the vein, artery or other tissue inwhich the shape memory catheterization device is deployed.

While the catheterization shape 122 is shown as cylindrical, othershapes are possible including a flattened cylinder, and other shapes,based on the particular method of deformation and further based on thedesired shape for catheterization. Further, while the original shape 120is shown as cylindrical, other regular geometrical shapes such asspherical, pyramidal, etc. could likewise be employed as well as anynumber of irregular shapes, based on the desired shape for deployment ofthe shape memory member 100.

It should be noted that the shape memory member 100 can be detached fromthe delivery rod 150 after being placed in the proper tissue locationfor deployment and left in the patient. In embodiments where the shapememory member 100 includes a shape memory polymer, the shape memorypolymer can be doped with a drug, such as an anticoagulant to reducingclotting, a drug to promote acceptance of the device by the surroundingtissue or other drug.

FIG. 14 is a pictorial representation of the transformation of a shapememory member of in accordance with an embodiment the present invention.In particular, a shape memory member 100 is presented as a cylinder.Examples of such shape memory members include a cylindrical cup forholding a drug for intravenous deployment. In the configuration shown,the closed end of the cup is fitted to a delivery rod 150, (the end ofwhich is shown schematically) and the inner portion of the cup is packedwith the drug to be deployed via the open end 121 and is then deformedfrom an original shape 120 into a catheterization shape 123 viacrimping. As shown the open end 121 of the original shape 120 is closedin the catheterization shape 123 to hold the drug for catheterization ina pocket 125 for deployment. When the shape memory member 100 is heatedduring deployment, it transforms into transformed shape 124 that issubstantially the original shape 120, subject to, for example, physicalconformity to the tissue, such as the vein, artery or other tissue inwhich the shape memory device is deployed. The end 121 of the cup opensfor release of the drug.

While the catheterization shape 122 is shown as cylindrical, othershapes are possible including a flattened cylinder, and other shapes,based on the particular method of deformation and further based on thedesired shape for catheterization. Further, while the original shape 120is shown as cylindrical, other regular geometrical shapes such asspherical, pyramidal, etc. could likewise be employed as well as anynumber of irregular shapes, based on the desired shape for deployment ofthe shape memory member.

It should be noted that the shape memory member 100 can remain attachedto the delivery rod 150 after being placed in the proper tissue locationfor deployment and removed from the patient after the drug is released.In embodiments where the shape memory member includes a shape memorypolymer, the shape memory polymer can also be doped with a drug, such asan anticoagulant to reducing clotting, or other drug.

FIG. 15 is a pictorial representation of the transformation of a shapememory member of in accordance with an embodiment the present invention.In particular, a shape memory member 100 is presented as a cylinder.Examples of such shape memory members include a cylindrical with aspherical pocket 126 for holding a drug for intravenous deployment. Inthe configuration shown, the cylinder is fitted to a delivery rod 150,(the end of which is shown schematically) and the pocket 126 is packedwith the drug to be deployed and is then deformed from an original shape125 into a catheterization shape 127 via crimping a portion of thecylinder shown. As shown, the pocket 126 of the original shape 125 isclosed in the catheterization shape 127 to hold the drug forcatheterization in a pocket 126 for deployment. When the shape memorymember 100 is heated during deployment, it transforms into transformedshape 129 that is substantially the original shape 125, subject to, forexample, physical conformity to the tissue, such as the vein, artery orother tissue in which the shape memory device is deployed. The pocket126 opens for release of the drug.

While the catheterization shape 127 is shown as cylindrical, othershapes are possible including a flattened cylinder, and other shapes,based on the particular method of deformation and further based on thedesired shape for catheterization. Further, while the original shape 125is shown as cylindrical, other regular geometrical shapes such as aspherical, pyramidal, etc. could likewise be employed as well as anynumber of irregular shapes, based on the desired shape for deployment ofthe shape memory member. In a further embodiment, the shape memorymember can be a hollow cup that is crimped to hold the ball end of amedical device and that releases the ball end for deployment. Further,while a single pocket 126 is shown, a shape memory member 100 withmultiple pockets could be implemented in a similar fashion.

It should be noted that the shape memory member 100 can remain attachedto the delivery rod 150 after being placed in the proper tissue locationfor deployment and removed from the patient after the drug is released.Delivery rod 150 includes a plurality of electrodes 130 and 132 thatelectrically couple to the shape memory member 100. In operation, theelectrodes couple a transformation data generator 110 to a capacitive,resistive element or an inductive element of shape memory member 100 ora strain gage coupled thereto. The plurality of electrodes areelectrically coupled to a portion of the shape memory member 100 todetect a change in resistance, capacitance or inductance of the shapememory member caused by the shape transformation of the shape memorymember 100 during deployment.

The plurality of electrodes 130 and 132 can be formed of a biocompatiblewire or foil such as gold or other biocompatible metal or metal alloy, ashape memory polymer with electrically conductive properties, such as ashape memory polymer that is surface doped with a conductive compound.In a further example the plurality of electrodes 130 and 132 can beformed a flexible conductive foam member or insert or other conductivemember.

In embodiments where the shape memory member 100 includes a shape memorypolymer, the shape memory polymer can also be doped with a drug, such asan anticoagulant to reducing clotting, or other drug. While a particularmedical device is shown, other medical devices can similarly bedeployed. Further, while the medical device is shown with a ball end,other catch designs including a pyramidal catch, a box catch or othershapes can likewise be implemented.

FIG. 16 is a pictorial representation of the transformation of a shapememory member of in accordance with an embodiment the present invention.In particular, a shape memory member 100 is shown along with electrodes130 and 132 that electrically couple to the shape memory member. Theelectrodes can be part of a delivery rod such as delivery rod 150, notspecifically shown.

In various embodiments, the shape memory member 100 can be detached fromthe delivery rod 150 after being placed in the proper tissue locationfor deployment and left in the patient. In these embodiments, theplurality of electrodes 130 and 132 decouple from the shape memorymember 100 when the shape memory member 100 is detached from thedelivery rod 150. In embodiments where the shape memory member 100remains attached to the delivery rod and is removed from the patient'sbody after treatment the electrodes 130 and 132 can be more permanentlyattached to the shape memory member 100.

In operation, the electrodes couple a transformation data generator 110to a resistive element or an inductive element of shape memory member100. As previously discussed, the shape memory member can be a shapememory polymer with electrically resistive or inductive properties, thatis surface doped with a conductive or partially conductive compound, orthat is doped to saturation with a conductive or partially conductivecompound. In a further example the shape memory member can be formed ofa shape memory polymer to include a flexible resistive or inductivemember such as a metallic foil element adhered or deposited on thesurface of the shape memory member, a flexible foil or coil insert, aresistive foam member or insert or other resistive or inductive member.In addition, the shape memory member can be formed of a shape memoryalloy that is electrically conductive with either a resistance orinductance that changes in response to the shape transformation of theshape memory member 100.

The plurality of electrodes 130 and 132 can be formed of a biocompatiblewire or foil such as gold or other biocompatible metal or metal alloy, ashape memory polymer with electrically conductive properties, such as ashape memory polymer that is surface doped with a conductive compound.In a further example the plurality of electrodes 130 and 132 can beformed a flexible conductive foam member or insert or other conductivemember.

FIG. 17 is a pictorial representation of the transformation of a shapememory member of in accordance with an embodiment the present invention.As in the embodiment of FIG. 16 , a shape memory member 100 is shownalong with electrodes 130 and 132 that electrically couple to the shapememory member. In this embodiment, the electrodes couple atransformation data generator 110 to a capacitive element of shapememory member 100 via conductive plates 134 and 136. The plates 134 and136 can be constructed of metallic foil elements adhered or deposited onthe surface of the shape memory member, conductive foam members orinserts or other conductive member. The shape memory element 100 can bedoped with an electrolytic compound to increase the capacitance of thedevice.

FIG. 18 is a pictorial representation of the transformation of a shapememory member of in accordance with an embodiment the present invention.As in the embodiment of FIGS. 16 and 17 , a shape memory member 100 isshown along with electrodes 130 and 132 that electrically couple to theshape memory member. In this embodiment, the electrodes couple atransformation data generator 110 to a strain gage 136 of shape memorymember 100. The strain gage can be constructed of metallic foil elementsadhered or deposited on the surface of the shape memory member,conductive foam members or inserts or other strain gage configurations.

FIG. 19 is a pictorial representation of the transformation of a shapememory member of in accordance with an embodiment the present invention.In particular, a shape memory member 100 is presented as a coil.Examples of such shape memory members include a coil constructed withshape memory alloy or shape memory polymer to treat an aneurism byfilling a weakened portion of a vein or artery. In the configurationshown, the shape memory member 100 is fitted on a catheter (not shown)and is deformed from an original shape 140 into a catheterization shape142. When the shape memory member 100 is heated during deployment, ittransforms into transformed shape 144 that is substantially the originalshape 140, subject to, for example, physical conformity to the tissue,such as the vein, artery or other tissue in which the shape memorycatheterization device is deployed.

The shape memory member 100 can be constructed of a resistive orconductive wire or other resistive or conductive material that isbiocompatible. The shape transformation of the shape memory member 100can be detected based on a change of resistance or inductance of theshape memory member.

It should be noted that the shape memory member 100 can be detached fromthe delivery rod 150 after being placed in the proper tissue locationfor deployment and left in the patient. In embodiments where the shapememory member includes a shape memory polymer, the shape memory polymercan be doped with a drug, such as an anticoagulant to reducing clotting,a drug to promote acceptance of the device by the surrounding tissue orother drug.

FIG. 20 is a pictorial representation of the transformation of a shapememory member of in accordance with an embodiment the present invention.In particular, a shape memory member 100 is presented as a cylinder.Examples of such shape memory members include a cylinder with aspherical pocket 126 for holding a medical device 146 such as a coil forintravenous deployment for treatment of an aneurism.

In the configuration shown, the shape memory member 100 is fitted to adelivery rod 150, (the end of which is shown schematically) and thepocket 126 is packed with a catch, such as a ball end of the medicaldevice 146 to be deployed. The shape memory device 100 is then deformedfrom an original shape 145 into a catheterization shape 147 via crimpinga portion of the cylinder shown. As shown, the pocket 146 of theoriginal shape 145 is closed in the catheterization shape 147 to holdthe ball end medical device for catheterization in the pocket 126 fordeployment. When the shape memory member 100 is heated duringdeployment, it transforms into transformed shape 149 that issubstantially the original shape 125, subject to, for example, physicalconformity to the tissue, such as the vein, artery or other tissue inwhich the shape memory device is deployed. The pocket 126 opens forrelease of the medical device 146. In the embodiment shown, the medicaldevice 146 is itself constructed of a shape memory member, such as ashape memory wire, alloy or polymer that is compressed into acatheterization shape and that expands to its own transformed shape fortreatment.

While the catheterization shape 147 is shown as cylindrical, othershapes are possible including a flattened cylinder, and other shapes,based on the particular method of deformation and further based on thedesired shape for catheterization. Further, while the original shape 145is shown as cylindrical, other regular geometrical shapes such asspherical, pyramidal, etc. could likewise be employed as well as anynumber of irregular shapes, based on the desired shape for deployment ofthe shape memory member. Further, while a single pocket 146 is shown, ashape memory member 100 with multiple pockets could be implemented in asimilar fashion.

It should be noted that the shape memory member 100 can remain attachedto the delivery rod 150 after being placed in the proper tissue locationfor deployment and removed from the patient after the medical device 146is released. Delivery rod 150 includes a plurality of electrodes 130 and132 that electrically couple to the shape memory member 100. Inoperation, the electrodes couple a transformation data generator 110 toa capacitive, resistive element or an inductive element of shape memorymember 100 or a strain gage coupled thereto. The plurality of electrodesare electrically coupled to a portion of the shape memory member 100 todetect a change in resistance, capacitance or inductance of the shapememory member caused by the shape transformation of the shape memorymember 100 during deployment.

The plurality of electrodes 130 and 132 can be formed of a biocompatiblewire or foil such as gold or other biocompatible metal or metal alloy, ashape memory polymer with electrically conductive properties, such as ashape memory polymer that is surface doped with a conductive compound.In a further example the plurality of electrodes 130 and 132 can beformed a flexible conductive foam member or insert or other conductivemember.

In embodiments where the shape memory member 100 includes a shape memorypolymer, the shape memory polymer can also be doped with a drug, such asan anticoagulant to reducing clotting, or other drug.

FIGS. 21 and 22 present pictorial representations of a shape memorymember and delivery rod in accordance with an embodiment the presentinvention. Like the embodiment of FIG. 19 , a shape memory member 100 ispresented as a coil such as a coil constructed with shape memory alloyor shape memory polymer for to treat an aneurism by filling a weakenedportion of a vein or artery. In the configuration shown, the shapememory member 100 is fitted on a delivery rod 150 and is deformed froman original shape shown in FIG. 21 into a catheterization shape shown inFIG. 22 . When the shape memory member 100 is heated during deployment,it transforms into transformed shape that is substantially the originalshape, subject to, for example, physical conformity to the tissue, suchas the vein, artery or other tissue in which the shape memorycatheterization device is deployed.

It should be noted that the shape memory member 100 can be detached fromthe delivery rod 150 after being placed in the proper tissue locationfor deployment and left in the patient. Delivery rod 150 includes aplurality of electrodes 130 and 132 that electrically couple to theshape memory member 100 and that decouple from the shape memory member100 when the shape memory member 100 is detached from the delivery rod150. In operation, the electrodes couple a transformation data generator110 to a capacitive, resistive element or an inductive element of shapememory member 100 or a strain gage coupled thereto. The plurality ofelectrodes 130 and 132 are electrically coupled to a portion of theshape memory member 100 to detect a change in resistance, capacitance orinductance of the shape memory member caused by the shape transformationof the shape memory member 100 during deployment.

The plurality of electrodes 130 and 132 can be formed of a biocompatiblewire or foil such as gold or other biocompatible metal or metal alloy, ashape memory polymer with electrically conductive properties, such as ashape memory polymer that is surface doped with a conductive compound.In a further example, the plurality of electrodes 130 and 132 can beformed a flexible conductive foam member or insert or other conductivemember. It should be noted that the shape memory member 100 can bedetached from the delivery rod 150 and electrodes 130 and 132 afterbeing placed in the proper tissue location for deployment and left inthe patient.

FIG. 23 is a pictorial representation of a shape memory member andcatheter in accordance with an embodiment the present invention. Inparticular, a cross section is shown of a cylindrical shape memorymember 100 and electrodes 130 and 132. In this embodiment the electrodesare arc shaped to conform with the outer surface of the cylindricalshape memory member 100. While each electrode 130 or 132 is shown as asingle homogeneous element, each electrode can include a central palmand a plurality of fingers each having a longitudinal axis along thelongitudinal axis of the cylindrical shape memory member 100. In thisconfiguration, the fingers of each electrode lend themselves to beingcrimped into a position of contact when the shape memory member 100 isdeformed for catheterization and to remain in contact with the shapememory member 100 when the shape memory member 100 undergoes its shapetransformation.

FIG. 24 is a flowchart representation of an embodiment of a method inaccordance with the present invention. In particular, a method ispresented for use in conjunction with one or more features and functionsdescribed in conjunction with FIGS. 1-23 . Step 400 includesendovascular insertion of the shape memory member via a catheter,wherein the shape memory member has a transition temperature that ishigher than a normal body temperature of the patient. Step 402 includesheating the shape memory member above the transition temperature. Step404 includes driving a circuit that includes at least one resistiveelement of the shape memory member. Step 406 includes generatingtransformation data based on a resistance of the at least one resistiveelement, wherein the transformation data indicates a shapetransformation of the shape memory catheterization device from acatheterization shape to a transformed shape.

In an embodiment, the transformation data is generated to indicate theshape transformation of the shape memory member from the catheterizationshape to the transformed shape when the resistance of the at least oneresistive element compares favorably to a transformation threshold. Thetransformation data can includes a data flag having a first value thatindicates the catheterization shape and a second value that indicatesthe transformed shape.

The shape memory catheterization device can include an endovascularstent for treating a blocked artery, an endovascular stent for treatingan arterial aneurism. The shape memory catheterization device canintravenously deploy a drug or a medical device in response to the shapetransformation of the shape memory member from the catheterization shapeto the transformed shape. The shape memory member can be doped tointravenously deploy a drug.

FIG. 25 is a flowchart representation of an embodiment of a method inaccordance with the present invention. In particular, a method ispresented for use in conjunction with one or more features and functionsdescribed in conjunction with FIGS. 1-24 . Step 410 includes generatinga control signal for controlling the heat source based on thetransformation data. In an embodiment, a control signal is generated todiscontinue the heating of the shape memory member when thetransformation data indicates the shape transformation of the shapememory member from the catheterization shape to the transformed shape.

FIG. 26 is a flowchart representation of an embodiment of a method inaccordance with the present invention. In particular, a method ispresented for use in conjunction with one or more features and functionsdescribed in conjunction with FIGS. 1-25 . Step 420 includesendovascular insertion of the shape memory member via a delivery rodthrough a catheter, wherein the shape memory member has a transitiontemperature that is higher than a normal body temperature of thepatient. Step 422 includes heating the shape memory member above thetransition temperature. Step 424 includes driving a circuit thatincludes at least one capacitive element of the shape memory member.Step 426 includes generating transformation data based on a capacitanceof the at least one capacitive element, wherein the transformation dataindicates a shape transformation of the shape memory member from acatheterization shape to a transformed shape.

In an embodiment, the transformation data is generated to indicate theshape transformation of the shape memory member from the catheterizationshape to the transformed shape when the capacitance of the at least onecapacitive element compares favorably to a transformation threshold. Thetransformation data can includes a data flag having a first value thatindicates the catheterization shape and a second value that indicatesthe transformed shape.

The shape memory catheterization device can include an endovascularstent for treating a blocked artery, an endovascular stent for treatingan arterial aneurism. The shape memory catheterization device canintravenously deploy a drug or a medical device in response to the shapetransformation of the shape memory member from the catheterization shapeto the transformed shape. The shape memory member can be doped tointravenously deploy a drug.

FIG. 27 is a flowchart representation of an embodiment of a method inaccordance with the present invention. In particular, a method ispresented for use in conjunction with one or more features and functionsdescribed in conjunction with FIGS. 1-26 . Step 430 includesendovascular insertion of a shape memory member via a delivery rodthrough a catheter, wherein the shape memory member has a transitiontemperature that is higher than a normal body temperature of thepatient. Step 432 includes heating the shape memory member above thetransition temperature. Step 434 includes driving a circuit thatincludes at least one inductive element of the shape memory member. Step436 includes generating transformation data based on an inductance ofthe at least one inductive element, wherein the transformation dataindicates a shape transformation of the shape memory member from acatheterization shape to a transformed shape.

In an embodiment, the transformation data is generated to indicate theshape transformation of the shape memory member from the catheterizationshape to the transformed shape when the inductance of the at least oneinductive element compares favorably to a transformation threshold. Thetransformation data can includes a data flag having a first value thatindicates the catheterization shape and a second value that indicatesthe transformed shape.

The shape memory catheterization device can include an endovascularstent for treating a blocked artery, an endovascular stent for treatingan arterial aneurism. The shape memory catheterization device canintravenously deploy a drug or a medical device in response to the shapetransformation of the shape memory member from the catheterization shapeto the transformed shape. The shape memory member can be doped tointravenously deploy a drug.

FIG. 28 is a flowchart representation of an embodiment of a method inaccordance with the present invention. In particular, a method ispresented for use in conjunction with one or more features and functionsdescribed in conjunction with FIGS. 1-27 . Step 440 includesendovascular insertion of the shape memory member via a delivery rodthrough a catheter, wherein the shape memory member has a transitiontemperature that is higher than a normal body temperature of thepatient. Step 442 includes heating the shape memory member above thetransition temperature. Step 444 includes driving a circuit thatincludes at least one strain gage coupled to the shape memory member.Step 446 includes generating transformation data based on a strainindicated by the at least one strain gage, wherein the transformationdata indicates a shape transformation of the shape memory member from acatheterization shape to a transformed shape.

In an embodiment, the transformation data is generated to indicate theshape transformation of the shape memory member from the catheterizationshape to the transformed shape when the strain indicated by the at leastone strain gage element compares favorably to a transformationthreshold. The transformation data can includes a data flag having afirst value that indicates the catheterization shape and a second valuethat indicates the transformed shape.

The shape memory catheterization device can include an endovascularstent for treating a blocked artery, an endovascular stent for treatingan arterial aneurism. The shape memory catheterization device canintravenously deploy a drug or a medical device in response to the shapetransformation of the shape memory member from the catheterization shapeto the transformed shape. The shape memory member can be doped tointravenously deploy a drug.

FIG. 29 is a flowchart representation of an embodiment of a method inaccordance with the present invention. In particular, a method ispresented for use in conjunction with one or more features and functionsdescribed in conjunction with FIGS. 1-28 . Step 450 includesendovascular insertion of a shape memory member via a delivery rodthrough a catheter, wherein the shape memory member has a transitiontemperature that is higher than a normal body temperature of the patientand wherein the catheter includes a plurality of electrodes that arecrimped for electrical coupling to the shape memory member duringtransformation of the shape memory member from an original shape into acatheterization shape. Step 452 includes heating the shape memory memberabove the transition temperature. Step 454 includes electrically drivinga circuit that includes an element of the shape memory member coupledvia the plurality of electrodes. Step 456 includes generatingtransformation data in response to the circuit, wherein thetransformation data indicates a shape transformation of the shape memorymember from the catheterization shape to a transformed shape.

In an embodiment, the circuit is electrically driven by either a directcurrent or an alternative current. The shape memory catheterizationdevice can include an endovascular stent for treating a blocked arteryor an endovascular stent for treating an arterial aneurism. The shapememory catheterization device can intravenously deploy a drug inresponse to the shape transformation of the shape memory member from thecatheterization shape to the transformed shape. The shape memorycatheterization device can intravenously deploy a drug. The shape memorycatheterization device can intravenously deploy a medical device inresponse to the shape transformation of the shape memory member from thecatheterization shape to the transformed shape. The transformation datacan include a data flag having a first value that indicates thecatheterization shape and a second value that indicates the transformedshape.

FIG. 30 is a flowchart representation of an embodiment of a method inaccordance with the present invention. In particular, a method ispresented for use in conjunction with one or more features and functionsdescribed in conjunction with FIGS. 1-29 . Step 460 includes heating ashape memory member above a transition temperature of the shape memorymember, wherein the transition temperature that is higher than a normalbody temperature of the patient. Step 462 includes crimping a pluralityof electrodes of a catheter for electrical coupling to the shape memorymember during transformation of the shape memory catheterization devicefrom an original shape into a catheterization shape, while the shapememory catheterization device is above the transition temperature.

The shape memory catheterization device can include an endovascularstent for treating a blocked artery or an endovascular stent fortreating an arterial aneurism. The shape memory catheterization devicecan intravenously deploy a drug in response to the shape transformationof the shape memory member from the catheterization shape to thetransformed shape. The shape memory catheterization device canintravenously deploy a drug. The shape memory catheterization device canintravenously deploy a medical device in response to the shapetransformation of the shape memory member from the catheterization shapeto the transformed shape.

FIG. 31 is a schematic block diagram of an embodiment of a system formonitoring a scaffold 200 in accordance with the present invention. Inparticular, scaffold 200 may be a shape-memory polymer or other scaffoldmaterial adhered or otherwise attached to a pushing rod or otherdelivery rod for targeted delivery, preferably through a catheter. Thisscaffold may be impregnated by loaded with drugs, cells, or geneticmaterial (as in the case of gene therapy), or other therapeuticmaterials from therapeutic source 302.

A loading data generator 302 includes a driving circuit 312 that iselectrically coupled to drive an impedance of the scaffold 200. Adetection circuit 314 generates loading data 306 based on the impedanceof the scaffold 200, such as a capacitance, resistance, inductance orsome combination thereof. The loading data 306 uses the impedancemeasurement to indicate an amount of impregnation of the therapeuticmaterial in the scaffold 200, such as via a loading profile, anunloading profile or other function of the impedance of the scaffold200.

In one mode of operation, the therapeutic source 302 presents thetherapeutic material to the scaffold 200 for loading. The therapeuticmaterial may be present as a solid, liquid, solution, a colloid, such asa gel, emulsion, slurry or other form. The loading of the scaffold 200can be performed via absorption, deposition, doping, osmosis,implantation or other loading of the scaffold with the therapeuticmaterial from the therapeutic source 302. In one example of operation,the scaffold 200 may be doped with biocompatible nano-particles. Thenano-particles, such as gold nano-particles, are visible via externalimaging modalities, such as medical ultrasound. The nano-particles maybe spatially oriented in such a way as to provide a visual indication ofthe degree of degradation of the scaffold and therefore the degree oftherapeutic substance delivery. They also provide a way for a user toconfirm degradation is occurring or has completed. These nano-particlescan be sized to elute from the body as waste. In this way, the scaffoldmay be monitored non-invasively, in vivo.

The loading data generator 302 is electrically coupled to the scaffold200 to monitor the loading of the therapeutic material based on a changein impedance of the scaffold. In particular, the impedance of thescaffold 200 can be measured at a number of time points to allow foranalysis. These may include the time at which the scaffold 200 isunloaded and undelivered, the scaffold is loaded and undelivered, andvarious time points during which the scaffold is delivered and in theprocess of unloading. Here loading refers to the concentration oftherapeutic substance within the scaffold and delivery refers to thescaffold's location, whether the device is being externally tested orapplied internally or externally for therapeutic substance unloading.

The measurement of loading data 306 can be calibrated to provide areading that represents the true concentration of the therapeuticmaterial in the scaffold 200. In an embodiment, multiple impedances ofthe scaffold can be measured via three or more electrodes to provideseveral spatially diverse impedance measurements. The loading data 306can be spatially calibrated and spatially measured to provide, forexample, an image of the scaffold indicating resistance, capacitance,inductance or concentration measurements throughout the volume of thescaffold. These measurements may be used as a baseline for the scaffoldsinherent resistance, capacitance, inductance or concentration. Further,the baseline measurement may be used to provide a more accurate loadingreading.

Once the scaffold 200 is determined to be substantially or adequatelyloaded, the scaffold can be prepared for delivery or stored for lateruse. In pertinent part, the loading data 306 can include a data flag orother indication that the impregnation/loading of the therapeuticmaterial is complete. In the event of storage, the loading data 306 canbe measured again prior to mounting on a delivery rod or other deliverydevice or after mounting but prior to catheterization to ensure that thescaffold 200 remains adequately loaded.

In a further mode of operation, the loading data generator 302 canoptionally be electrically coupled to the scaffold 200 via the deliveryrod or other delivery device in order to monitor the loading and/orunloading of the therapeutic material from the scaffold before or afterdelivery. For example, the loading of the scaffold could be performedafter the scaffold is mounted on the delivery rod or other deliverydevice, and the loading data generator 302 can monitor the loading asdescribed above and determine, for example, when theimpregnation/loading is complete, adequately complete or substantiallycomplete. As discussed above, the loading data 306 can be measured againprior to catheterization to ensure that the scaffold 200 remainsadequately loaded or to provide a first baseline reading.

In examples where the scaffold 200 remains attached to the catheterdelivery rod, the loading data 306 can be measured shortly afterdelivery in situ via catheterization to provide a further baselinereading for monitoring the unloading of the therapeutic material fromthe scaffold 200. The loading data 306 can be analyzed to track anunloading profile of the therapeutic material and further can provide anindication that the therapeutic material is adequately unloaded, i.e.that the desired amount of therapeutic material has been delivered bythe scaffold to the patient in proximity to the site of the delivery.Once the loading data 306 indicates that unloading is complete thescaffold can be removed from the patient, such as by retracting thedelivery rod through the catheter.

While the loading data generator 302 is described above in conjunctionwith the measurement of one or more impedances associated with thescaffold 200, in other embodiments, loading data generator 302 canmeasure other properties in addition to or in place of impedance. Forexample, loading data generator 302 can include a driver and detectorcoupled to the scaffold 200 that measure a spectral conductance,transmission or absorption of a light wave that is transmitted throughthe scaffold 200. In a further example, loading data generator 302 caninclude a driver and detector coupled to the scaffold 200 that measure aspectral conductance, transmission or absorption of a millimeter wave orother RF signal transmitted through the scaffold 200. In pertinent part,loading data generate 306 interacts with the scaffold 200 viameasurements to monitor the loading and unloading of the therapeuticmaterial from the scaffold 200. The detection circuit 314 can include aprocessor or other processing device or circuit.

Further embodiments that include several optional functions and featureswill be described in conjunction with FIGS. 32-47 that follow.

FIG. 32 is a schematic block diagram of an embodiment of a system formonitoring a scaffold 200 in accordance with the present invention. Inparticular, a system is shown that is similar to the systems describedin conjunction with FIGS. 1-30 where similar elements are referred to bycommon reference numerals. In this embodiment however, the scaffold 200is either itself a shape memory member that operates in place of shapememory member 100 or is released by a shape memory member 100.

Consider first the example where the scaffold 200 is itself a shapememory member. In this example, the shape memory catheterization device98 includes a catheter having a delivery rod 150 for use in conjunctionwith a catheterization procedure involving the insertion of the shapememory catheterization device 98 into a patient. Examples of suchcatheterization procedures include the insertion of an endovascularstent as part of an angioplasty or treatment of an aneurism or theintravenous deployment of another medical device, an intravenous drugdeployment or the administration of anesthetic medication into theepidural space, the subarachnoid space, or around a major nerve bundlesuch as the brachial plexus, the administration of anesthetic medicationinto the epidural space, the subarachnoid space, or around a major nervebundle such as the brachial plexus, an in vitro fertilization or othermedical treatment, a urinary catheterization, treatment of an abdominalabscess, a balloon septostomy, balloon sinuplasty, catheter ablation, anin vitro fertilization or other medical treatment.

The shape memory catheterization device 98 includes a scaffold 200 thatis implemented via a shape memory member having a transition temperaturethat is higher than a normal body temperature of the patient. When heatis applied by a heat source 104 the scaffold 200 of shape memorycatheterization device 98 is heated above the transition temperaturecauses the scaffold to undergo a shape transformation from acatheterization shape into a transformed shape that is useful in theparticular treatment. The heat source 104 can be an infrared emitter,laser or other light source, a heating coil or other electrical heatingsource, a microwave source or other electromagnetic source, a radiationsource or other heat source. While shown separately from the shapememory catheterization device 98, the heat source 104 can be integratedinto the shape memory catheterization device 98.

The transformation data generator 102 includes a driver circuit 112 andgenerates transformation data 106 based on feedback generated by thedetection circuit 114. The transformation data 106 indicates a shapetransformation of the scaffold 200 of the shape memory catheterization98 device from the catheterization shape to the transformed shape. In anembodiment of the present invention the transformation data 106 can bedisplayed or otherwise used to provide visual, audible or tactilefeedback to the users of shape memory catheterization device 98 that theshape memory member 100 has reached its transformation shape. Thedetection circuit 114 can include a processor or other processingdevice.

In second example, a shape memory member 100 provides a releasemechanism for the scaffold 200. In an embodiment, the shape memorymember 100 can remain attached to the delivery rod 150 after beingplaced in the proper tissue location for deployment and removed from thepatient after the scaffold 200 is released. An example of such a shapememory member 100 includes a cylindrical cup for holding a scaffold 200for intravenous deployment. In the configuration shown, the closed endof the cup is fitted to a delivery rod 150, (the end of which is shownschematically) and the inner portion of the cup is packed with thescaffold to be deployed via an open end and is then deformed from anoriginal shape into a catheterization shape via crimping. When the shapememory member 100 is heated during deployment, it transforms into atransformed shape that is substantially the original shape, subject to,for example, physical conformity to the tissue, such as the vein, arteryor other tissue in which the shape memory device is deployed. The cupopens for release of the scaffold.

FIG. 33 is a schematic block diagram of an embodiment of a system formonitoring a scaffold 200 in accordance with the present invention. Asdiscussed in conjunction with FIG. 31 , the scaffold 200 can bedelivered via a scaffold catheterization device 298 that includescatheter delivery rod 150, such as a push rod or other deliverymechanism. In a further mode of operation, the loading data generator302 can optionally be electrically coupled to the scaffold 200 via thedelivery rod or other delivery device in order to monitor the loadingand/or unloading of the therapeutic material from the scaffold before orafter delivery.

In the example shown, the loading of the scaffold 200 via therapeuticsource 302 is performed after the scaffold is mounted on thecatheterization delivery rod 150. The loading data generator 302monitors the loading as previously described and can determine, forexample, when the impregnation/loading is complete. As discussed above,the loading data 306 can be measured again prior to catheterization toensure that the scaffold 200 remains adequately loaded or to provide afirst baseline reading.

In examples where the scaffold 200 remains attached to the catheterdelivery rod 150, the loading data 306 can be measured shortly afterdelivery in situ via catheterization to provide a further baselinereading for monitoring the unloading of the therapeutic material fromthe scaffold 200. The loading data 306 can be analyzed to track anunloading profile of the therapeutic material and further can provide anindication that the therapeutic material is adequately unloaded, i.e.that the desired amount of therapeutic material has been delivered bythe scaffold to the patient in proximity to the site of the delivery.Once the loading data 306 indicates that unloading is complete thescaffold 200 can be removed from the patient, such as by retracting thedelivery rod through the catheter.

FIG. 34 is a schematic block diagram of an embodiment of a system formonitoring a scaffold 200 in accordance with the present invention. Asdiscussed in conjunction with FIGS. 31 and 33 , the scaffold 200 can bedelivered via a scaffold catheterization device 298 that includescatheter delivery rod 150, such as a push rod or other deliverymechanism. In a further mode of operation, the loading data generator302 can optionally be electrically coupled to the scaffold 200 via thedelivery rod or other delivery device in order to monitor the loadingand/or unloading of the therapeutic material from the scaffold before orafter delivery.

In the example shown, the loading of the scaffold 200 via therapeuticsource 302 is performed prior to the scaffold being mounted on thecatheterization delivery rod 150. The loading data generator 302monitors the loading as previously described and the loading data 306can be measured prior to mounting on the catheterization delivery rod150 and/or after mounting but prior to catheterization to ensure thatthe scaffold 200 remains adequately loaded. Further, the loading data306 can be measured shortly after delivery in situ via catheterizationto provide a further baseline reading for monitoring the unloading ofthe therapeutic material from the scaffold 200.

The loading data 306 can be analyzed to track an unloading profile ofthe therapeutic material and further can provide an indication that thetherapeutic material is adequately unloaded, i.e. that the desiredamount of therapeutic material has been delivered by the scaffold to thepatient in proximity to the site of the delivery. Once the loading data306 indicates that unloading is complete, the scaffold 200 can beremoved from the patient, such as by retracting the delivery rod throughthe catheter.

FIG. 35 is a graphical representation of a loading profile in accordancewith an embodiment the present invention. In particular, a scaffoldimpedance, Z, is presented as a function of time during loading oftherapeutic material in a scaffold, such as scaffold 200. As previouslydiscussed, the impedance Z can represent a resistive impedance, acapacitive impedance, an inductive impedance or a combination thereof.While represented as a scalar quantity, the real portion, imaginaryportion, the angle and/or the magnitude of the impedance can be used forsimilar purposes. As shown, the loading profile 252 indicates a changein impedance from the origin when loading begins, to a time T_(L), wherea loading threshold 250 is reached—indicating that that scaffold isadequately loaded.

It should be noted that while the loading profile is shown as amonotonically increasing function of increased concentration of thetherapeutic material from an unloaded condition to a loaded condition,other functions, such as monotonically decreasing function or otherfunctions can likewise be used, based on the composition of the scaffold200, the nature of the therapeutic material in conjunction with theproperties of any carrier used therewith such as a gel, solution, solidor other carrier.

In operation, the loading data generator 302 generates loading data 306that indicate the loading profile 250, that provides specific data flagsthat indicates events such as certain benchmarks in loading completions(10%, 20%, 30% . . . ) and/or a further flag that indicates that theloading threshold 250 has been reached.

As described in conjunction with FIG. 31 , loading data generator 302can measure other properties in addition to or in place of impedance.For example, loading data generator 302 can include a driver anddetector coupled to the scaffold 200 that measure a spectralconductance, transmission or absorption of a light wave that istransmitted through the scaffold 200. In a further example, loading datagenerator 302 can include a driver and detector coupled to the scaffold200 that measure a spectral conductance, transmission or absorption of amillimeter wave or other RF signal transmitted through the scaffold 200.In pertinent part, loading data generate 306 interacts with the scaffold200 via measurements to monitor the loading and unloading of thetherapeutic material from the scaffold 200. In these further examples,loading data 306 can be generated based on loading profiles that presentother quantities such as conductance, transmission or absorption oflight or RF waves as a function of time as the concentration of thetherapeutic material increases during loading.

FIG. 36 is a graphical representation of an unloading profile inaccordance with an embodiment the present invention. In particular, ascaffold impedance, Z, is presented as a function of time duringunloading of therapeutic material from a scaffold, such as scaffold 200.As previously discussed, the impedance Z can represent a resistiveimpedance, a capacitive impedance, an inductive impedance or acombination thereof. While represented as a scalar quantity, the realportion, imaginary portion, the angle and/or the magnitude of theimpedance can be used for similar purposes. As shown, the unloadingprofile 262 indicates a change in impedance from the origin when loadingbegins to a time T_(U), where an unloading threshold 260 isreached—indicating that that scaffold is adequately unloaded.

It should be notes that while the unloading profile is shown as amonotonically decreasing function of decreased concentration of thetherapeutic material from an loaded condition to an unloaded condition,other functions, such as monotonically increasing function or otherfunctions can likewise be used, based on the composition of the scaffold200, the nature of the therapeutic material in conjunction with theproperties of any carrier used therewith such as a gel, solution, solidof other carrier.

In operation, the loading data generator 302 generates loading data 306that indicate the unloading profile 260, that provides specific dataflags that indicates events such as certain benchmarks in unloadingcompletions (10%, 20%, 30% . . . ) and/or a further flag that indicatesthat the unloading threshold 260 has been reached.

As described in conjunction with FIGS. 31 and 35 , loading datagenerator 302 can measure other properties in addition to or in place ofimpedance. For example, loading data generator 302 can include a driverand detector coupled to the scaffold 200 that measure a spectralconductance, transmission or absorption of a light wave that istransmitted through the scaffold 200. In a further example, loading datagenerator 302 can include a driver and detector coupled to the scaffold200 that measure a spectral conductance, transmission or absorption of amillimeter wave or other RF signal transmitted through the scaffold 200.In pertinent part, loading data generate 306 interacts with the scaffold200 via measurements to monitor the loading and unloading of thetherapeutic material from the scaffold 200. In these further examples,loading data 306 can be generated based on unloading profiles thatpresent other quantities such as conductance, transmission or absorptionof light or RF waves as a function of time as the concentration of thetherapeutic material decreases during unloading.

FIG. 37 is a schematic block diagram of an embodiment of a loading datagenerator in accordance with the present invention. In this embodiment,the scaffold 200 includes a resistive element that has a resistanceR_(s) that changes in response to the concentration of the therapeuticmaterial. For example, the scaffold can absorb, be doped, implanted withor otherwise carry a conductive or partially conductive therapeuticmaterial or carrier thereof.

The driver circuit includes a power source, such as the voltage sourceshown, that drives the detection circuit 114 and a wheatstone bridgeformed with the resistive element of the scaffold 200 and a plurality offixed resistors. The voltage detector 105 monitors the change inresistance of the resistive element of the scaffold and generates theloading data 306, for example, that indicates the resistance or thatindicates the change in resistance R_(s) indicates that loading orunloading has occurred.

In an embodiment, the loading data 306 can include a data flag having afirst value that indicates an unloaded condition and a second value thatindicates a loaded condition. The transition of the loading 306 from thefirst value to the second value can indicate that loading has occurred.The transition of the loading 306 from the second value to the firstvalue can indicate that unloading has occurred.

FIG. 38 is a schematic block diagram of an embodiment of a loading datagenerator in accordance with the present invention. In this embodiment,the scaffold 200 includes a capacitive element that has a capacitanceC_(s) that changes in response to the concentration of the therapeuticmaterial. For example, the scaffold have capacitive properties, that isincludes a plurality of plates that are surface doped with a conductiveor partially conductive compound, a metallic foil element adhered ordeposited on the surface of the shape memory member or a conductive foamor other conductive element that forms the plates. The scaffold furtherincludes an electrolytic, dielectric or insulator that is disposedbetween the plurality of plates, wherein the electrolytic, dielectric orinsulating properties changes the scaffold absorbs, be doped with,implanted with or otherwise carries therapeutic material or a carrierthereof.

The driver circuit 112 includes a power source, such as the voltagesource shown, that drives the detection circuit 114 via an alternatingcurrent such as the step waveform generator that is shown. The drivercircuit further includes a detection resistance R_(d) that forms an RCcircuit with the capacitive element of the scaffold 200. The voltagedetector 105 monitors the change in capacitance of the capacitiveelement of scaffold 200 based on monitoring the time of charging and/ordischarging of the capacitive element. The voltage detector generatesthe loading data 306, to indicate changes in capacitance C_(s).

In an embodiment, the loading data 306 can include a data flag having afirst value that indicates an unloaded condition and a second value thatindicates a loaded condition. The transition of the loading 306 from thefirst value to the second value can indicate that loading has occurred.The transition of the loading 306 from the second value to the firstvalue can indicate that unloading has occurred.

FIG. 39 is a schematic block diagram of an embodiment of a loading datagenerator in accordance with the present invention. In this embodiment,the scaffold 200 includes an inductive element that has an inductanceL_(s) that changes in response to the concentration of the therapeuticmaterial. For example, the scaffold can have electrically inductiveproperties, that is surface doped with a conductive or partiallyconductive compound, or that is doped to saturation with a conductive orpartially conductive compound. In a further example the scaffold 200 caninclude an inductive member such as a metallic foil element adhered ordeposited on the surface of the scaffold, a flexible foil or coilinsert, a conductive foam member or insert or other inductive member.For example, the scaffold can absorb, be doped, implanted with orotherwise carry a magnetically conductive or partially magneticallyconductive therapeutic material or carrier thereof.

The driver circuit 112 includes a power source, such as the voltagesource shown, that drives the detection circuit 114 via an alternatingcurrent such as the step waveform generator that is shown. The drivercircuit further includes a detection resistance R_(d) that forms an RLcircuit with the inductive element of the scaffold 200. The voltagedetector 105 monitors the change in inductance of the inductive elementof scaffold 200 based on monitoring the time of charging and/ordischarging of the inductive element. The voltage detector generates theloading data 306 to indicate changes in inductance L_(s).

In an embodiment, the loading data 306 can include a data flag having afirst value that indicates an unloaded condition and a second value thatindicates a loaded condition. The transition of the loading 306 from thefirst value to the second value can indicate that loading has occurred.The transition of the loading 306 from the second value to the firstvalue can indicate that unloading has occurred.

FIG. 40 is a pictorial diagram of a scaffold and catheter in accordancewith an embodiment of the present invention. In this embodiment, thescaffold 200 may be a shape-memory polymer or other biodegradablescaffold material delivered via a shape-memory polymer delivery deviceadhered to a delivery rod for targeted delivery, preferably through acatheter. The scaffold 200 can be placed in an area targeted fortreatment while the delivery rod will retract the delivery device. Thedelivery device may grip the scaffold as shown, however or othergripping mechanisms may be possible. This scaffold 200 may be loadedwith drugs, cells, or genetic material (as in the case of gene therapy),or other therapeutic substance. The loading of the scaffold 200 can bemeasured at a number of time points to allow for analysis.

In particular, an example is presented where a biodegradable scaffold200 is loaded with therapeutic material and delivered via a shape memorycatheterization device. In the state 220, the scaffold 200 is unattachedand unloaded. The scaffold 200 can be exposed to the therapeutic sourceto begin loading. The loading data generator 302 is electrically coupledto the scaffold 200 to monitor the loading of the therapeutic materialbased on a change in impedance of the scaffold. When the loading iscomplete, as indicated or confirmed by the loading data 306, the loaddata generator 302 is detached.

In the state 222, the scaffold 200 is unattached and loaded. Thescaffold 200 can be prepared for delivery or stored for later use. Inthe event of storage, the loading data 306 can be measured again priorto mounting on a delivery rod or other delivery device or after mountingbut prior to catheterization to ensure that the scaffold 200 remainsadequately loaded.

A shape memory member 100 is presented as a cylinder that is attached toa catheterization delivery rod 150 and is presented in its originalshape 223. The shape memory member 100 includes a spherical pocket 126for holding the scaffold 200. In the state 224, the loaded scaffold isattached. In the configuration shown, the pocket 126 is packed with thescaffold to be deployed and is then deformed from its original shapeinto a catheterization shape via crimping a portion of the cylindershown. As shown, the pocket 126 of the original shape 125 is closed inthe catheterization shape to hold the scaffold for catheterization in apocket 126 for deployment.

In state 226, the loaded scaffold is detached and delivered to a tissuesite 210 in a patient. When the shape memory member 100 is heated duringdeployment and transforms into transformed shape that is substantiallythe original shape, subject to, for example, physical conformity to thetissue, such as the vein, artery or other tissue in which the shapememory device is deployed. The pocket 126 opens for release of thescaffold 200 to the tissue site 210. In the state 228, the scaffoldunloads the therapeutic material at the tissue site 210 and can thenbiodegrade or otherwise remain or pass through the body without harm tothe patient.

While not specifically shown, the transformation data generator 102 iscoupled to the electrodes 130 and 132 to generate transformation data106 that indicates the shape transformation of the shape memory member100 as previously described.

The plurality of electrodes 130 and 132 can be formed of a biocompatiblewire or foil such as gold or other biocompatible metal or metal alloy, ashape memory polymer with electrically conductive properties, such as ashape memory polymer that is surface doped with a conductive compound.In a further example the plurality of electrodes 130 and 132 can beformed a flexible conductive foam member or insert or other conductivemember.

In embodiments where the shape memory member 100 includes a shape memorypolymer, the shape memory polymer can also be doped with a drug, such asan anticoagulant to reducing clotting, or other drug. While a particularscaffold 200 is shown, other medical devices can similarly be deployed.Further, while the scaffold is shown with a spherical shape, otherdesigns including a pyramid, a box or other shapes can likewise beimplemented.

FIG. 41 is a pictorial diagram of a scaffold and catheter in accordancewith an embodiment of the present invention. In particular, an exampleis presented where a biodegradable scaffold 230, a further example ofscaffold 200, is constructed of a shape memory material is loaded withtherapeutic material and delivered via a catheterization device. In thestate 240, a scaffold 230 is unattached and unloaded. The scaffold 230can be exposed to the therapeutic source to begin loading. The loadingdata generator 302 is electrically coupled to the scaffold 230 tomonitor the loading of the therapeutic material based on a change inimpedance of the scaffold via the electrodes 232 and 234. In particular,the optional electrodes the electrodes 232 and 234 are formed of a metalfoil adhered to the surface of the scaffold or other electrodes that areattached to the scaffold 230 to facilitate the connection to the loadingdata generator 302. While two electrodes are shown, a greater number canbe employed, particularly in circumstances where the impedance of thescaffold is measured at a plurality of different points in the scaffold.

In the state 242, the scaffold 230 is unattached and loaded. When theloading is complete, as indicated or confirmed by the loading data 306,the load data generator 302 can be detached. The scaffold 230 can beprepared for delivery or stored for later use. In the event of storage,the loading data 306 can be measured again prior to mounting on adelivery rod or other delivery device or after mounting but prior tocatheterization to ensure that the scaffold 230 remains adequatelyloaded.

In the state 244, the electrodes 232 and 234 are optionally removed fromthe scaffold 200 at some time prior to the attachment to thecatheterization delivery rod 150. In an embodiment, the scaffold 230 isbiodegradable and the electrodes 232 and 234 are formed of anon-biodegradable substance and can be removed prior to delivery. Inother embodiments, the electrodes 232 and 234 are biodegradable orotherwise biocompatible such as a biocompatible foil, conductive ink, abiodegradable polymer member doped with carbon nanotubes or goldnanoparticles, a conductive foam member or insert or other biodegradableor biocompatible conductive element. In this case, the electrodes 230and 232 can be included on the scaffold and/or not detached and furthercan be reused in connections to electrodes 130 and 132 of the deliveryrod 150.

In the state 245, the loaded scaffold 230 is attached to the deliveryrod 150. In the state 246, the scaffold 230 is then deformed from itsoriginal shape into a catheterization shape via crimping a portion ofthe cylinder shown. As shown, the electrodes 130 and 132 are crimped inplace and provide a connection to the scaffold 230 for catheterizationand delivery to a tissue site.

In state 248, the loaded scaffold is delivered to a tissue site 210 in apatient. When the scaffold 230 is heated during deployment andtransforms into transformed shape that is substantially the originalshape, subject to, for example, physical conformity to the tissue, suchas the vein, artery or other tissue in which the shape memory device isready to be released from the delivery rod 150. While not specificallyshown, the transformation data generator 102 is coupled to theelectrodes 130 and 132 to generate transformation data 106 thatindicates the shape transformation of the scaffold 230 as previouslydescribed.

In state 250, the loaded scaffold 230 is released at the tissue site210. In the state 252, the scaffold 230 unloads the therapeutic materialat the tissue site 210 and can then biodegrade or otherwise remain orpass through the body without harm to the patient.

FIG. 42 is a pictorial diagram of a scaffold and catheter in accordancewith an embodiment of the present invention. In particular, an exampleis presented where a scaffold 260, a further example of scaffold 200, isloaded with therapeutic material and delivered via a catheterizationdevice that monitors the unloading of the scaffold 260 and removes thescaffold from the body of the patent when unloading is complete.

In the state 270, a scaffold 260 is unattached and unloaded. Thescaffold 260 can be exposed to the therapeutic source to begin loading.The loading data generator 302 (not shown) is electrically coupled tothe scaffold 260 to monitor the loading of the therapeutic materialbased on a change in impedance of the scaffold via the electrodes 232and 234. In particular, the optional electrodes the electrodes 232 and234 are formed of a metal foil adhered to the surface of the scaffold orother electrodes that are attached to the scaffold 260 to facilitate theconnection to the loading data generator 302. While two electrodes areshown, a greater number can be employed, particularly in circumstanceswhere the impedance of the scaffold is measured at a plurality ofdifferent points in the scaffold.

In the state 272, the scaffold 260 is unattached and loaded. When theloading is complete, as indicated or confirmed by the loading data 306,the load data generator 302 can be detached. The scaffold 260 can beprepared for delivery or stored for later use. In the event of storage,the loading data 306 can be measured again prior to mounting on adelivery rod or other delivery device or after mounting but prior tocatheterization to ensure that the scaffold 260 remains adequatelyloaded.

In the state 272, the electrodes 232 and 234 are optionally removed fromthe scaffold 200 at some time prior to the attachment to thecatheterization delivery rod 150. In the embodiment shown, theelectrodes 230 and 232 are reused in connections to electrodes 130 and132 of the delivery rod 150. In the state 274, the loaded scaffold 260is attached to the delivery rod 150 and is delivered to a tissue site ina patient. While not specifically shown, the loading data generator 302is coupled to the electrodes 130 and 132 to generate further loadingdata 306 that indicates the unloading of the therapeutic material fromthe scaffold 260 as previously described. In the state 276, the scaffold260 unloads the therapeutic material at the tissue site. When theloading data 306 indicates the unloading is complete, the scaffold 260can be removed from the body of the patient by retracting the deliveryrod 150 via the catheter.

FIG. 43 is a flowchart representation of an embodiment of a method inaccordance with the present invention. In particular a method ispresented for use in conjunction with one or more functions and featurespresented in conjunction with FIGS. 1-42 . Step 420 includes providing ascaffold for impregnation with a therapeutic material. Step 422 includeselectrically driving an impedance of the scaffold. Step 424 includesgenerating loading data based on the impedance of the scaffold, whereinthe loading data indicates an amount of impregnation of the therapeuticmaterial in the scaffold.

In an embodiment, the loading data provides an indication when theimpregnation of the therapeutic material is complete. The scaffold canbe coupled to a delivery rod for the delivery in the patient viacatheterization. The driving circuit can be coupled to the scaffold viaa plurality of electrodes. The loading data can indicate a first loadingmeasurement prior to the catheterization, a second loading measurementwhen the scaffold is delivered in the patient, and a third loadingmeasurement when the scaffold is delivered in the patient, wherein thethird loading measurement indicates the therapeutic material is unloadedfrom the scaffold.

FIG. 44 is a flowchart representation of an embodiment of a method inaccordance with the present invention. In particular a method ispresented for use in conjunction with one or more functions and featurespresented in conjunction with FIGS. 1-43 . Step 400 includesendovascular insertion of a scaffold via a catheter, wherein thescaffold is impregnated with a therapeutic material. Step 402 includesdriving a circuit that includes an impedance of the scaffold. Step 404includes generating loading data based on the impedance of the scaffold,wherein the loading data indicates a delivery of the therapeuticmaterial from the scaffold. Step 406 includes determining that thedelivery of the therapeutic material is complete based on the loadingdata.

FIG. 45 is a flowchart representation of an embodiment of a method inaccordance with the present invention. In particular a method ispresented for use in conjunction with one or more functions and featurespresented in conjunction with FIGS. 1-44 . Step 410 includesimpregnating a scaffold with a therapeutic material. Step 412 includesdriving a circuit that includes an impedance of the scaffold. Step 414includes generating loading data based on the impedance of the scaffold,wherein the loading data indicates an amount of impregnation of thetherapeutic material in the scaffold. Step 416 includes determining thatthe impregnation of the therapeutic material is complete based on theloading data.

FIG. 46 is a schematic block diagram of an embodiment of driver circuitand detection circuit in accordance with the present invention. Inparticular a driver circuit 112 and detector circuit 114 are shown foruse in conjunction with a transformation data generator, such astransformation data generator 102.

While transformation data generator 102 has been primarily discussed interms of the measurement of strain, resistance, capacitance, inductanceor impedance other properties can be used in addition to or in place ofstrain, resistance, capacitance, inductance or impedance. In anembodiment, transformation data generator 102 include a driver 500 anddetector 502 coupled to the shape memory member 100 that measure aspectral conductance, reflection, transmission or absorption of a lightwave that is transmitted through the shape memory member 100. In afurther example, transformation data generator 102 can include a driver500 and detector 502 coupled to the shape memory member 100 that measurea spectral conductance, reflection, transmission or absorption of an RFwave such as a far-field or near field millimeter wave signal wave thatis transmitted through the shape memory member 100. While the driver 500and detector 502 are shown as being on opposing sides of shape memorymember 100, other configurations are likewise possible. It should benoted that this alternative mode of operation of transformation datagenerator 102 can be used in place of any of the prior embodimentsdiscussed in conjunction with FIGS. 1-30 and 32 .

In the operation of the transformation data generator 102, the driver500 of driver circuit 112 includes an RF transmitter having an antennaor coil or a light emitting element such as a light emitting diode, alaser diode or other miniature light source that produces an RF orlightwave that is transmitted into the shape memory member 100. Thetransformation data generator 102 also includes a detection circuit 114having a detector 502 that includes an antenna or coil and an RFreceiver or lightwave detector such as a photo detector, photocell ordetector that is coupled to a processor or other circuit included in thedetection circuit for generating transformation data 106. Thetransformation data 106 indicates a shape transformation of the shapememory member 100 device from the catheterization shape to thetransformed shape, based on changes in spectral conductance, reflection,transmission or absorption of the RF signal or lightwave driven to theshape memory member 100 by driver 500 and detected via detector 502. Inan embodiment of the present invention the transformation data 106 canbe displayed or otherwise used to provide visual, audible or tactilefeedback to the users of a shape memory catheterization device 98 thatthe shape memory member 100 has reached its transformation shape.

FIG. 47 is a schematic block diagram of an embodiment of driver circuitand detection circuit in accordance with the present invention. Inparticular, a driver circuit 312 and detector circuit 314 are shown foruse in conjunction with a loading data generator, such as loading datagenerator 302.

As previously discussed, loading data generator 302 can measure otherproperties in addition to or in place of resistance, capacitance,inductance or impedance. For example, loading data generator 302 caninclude a driver 500 and detector 502 coupled to the scaffold 200 or 230that measure a spectral conductance, reflection, transmission orabsorption of a light wave or RF wave that is transmitted into orthrough the scaffold 200 or 230. While the driver 500 and detector 502are shown as being on opposing sides of scaffold 200 or 230, otherconfigurations are likewise possible. It should be noted that thisalternative mode of operation of loading data generator 302 can be usedin place of any of the prior embodiments discussed in conjunction withFIGS. 31 and 33-45 .

In the operation of the loading data generator 302, the driver 500 ofdriver circuit 312 includes an RF transmitter having an antenna or coilor a light emitting element such as a light emitting diode, a laserdiode or other miniature light source that produces an RF or lightwavethat is transmitted into the scaffold 200 or 230. The loading datagenerator 302 also includes a detection circuit 314 having a detector502 that includes an antenna or coil and an RF receiver or lightwavedetector such as a photo detector, photocell or detector that is coupledto a processor or other circuit included in the detection circuit forgenerating loading data 306. The loading data generator 306 interactswith the scaffold 200 via measurements to monitor the loading andunloading of the therapeutic material from the scaffold 200. In thesefurther examples, loading data 306 can be generated based on loadingprofiles that present reflection, conductance, transmission orabsorption of either light or RF waves as a function of time as theconcentration of the therapeutic material increases during loadingand/or unloading. In an embodiment of the present invention the loadingdata 306 can be displayed or otherwise used to provide visual, audibleor tactile feedback to the users of a scaffold 200 or 230 that thescaffold 200 or 230 has been loaded or unloaded, partially loaded,loading or unloading has begun, is at a particular point on a loading orunloading profile, etc.

FIG. 48 is a schematic block diagram of an embodiment of a system formonitoring a scaffold 200′ in accordance with the present invention. Inparticular, a scaffold 200′ is presented this is similar to scaffold 200discussed in conjunction with FIGS. 31 and 33 except that a loading datagenerator 302′, similar to loading data generator 302 is attached to orincorporated in the scaffold 200′ and communicates loading data 306wirelessly with a wireless loading data receiver 510. Like scaffold 200,scaffold 200′ can be delivered via a scaffold catheterization device 298that includes catheter delivery rod 150, such as a push rod or otherdelivery mechanism. The loading data generator 302′ can be coupled tothe scaffold 200′ to monitor the loading of the therapeutic material tothe scaffold before delivery. In this embodiment, the loading datagenerator 302′ is also capable of monitoring the unloading of thetherapeutic material from the scaffold 200′ after delivery in thepatient and further after the scaffold 200′ is detached from thecatheter delivery rod 150.

The wireless loading data receiver receives the loading data 306 fromthe loading data generator 302′. The loading data 306 can be analyzed totrack an unloading profile of the therapeutic material and further canprovide an indication that the therapeutic material is adequatelyunloaded, i.e. that the desired amount of therapeutic material has beendelivered by the scaffold to the patient in proximity to the site of thedelivery.

FIG. 49 is a schematic block diagram of an embodiment of a loading datagenerator in accordance with the present invention. A loading datagenerator 302′ is shown that provides many of the functions and featuresdescribed in conjunction with loading data generator 302. In particular,loading data generator 302′ includes a driving circuit 312 that, forexample, is electrically coupled to drive an impedance of the scaffold200′. In this case, the detection circuit 314 generates loading data 306based on the impedance of the scaffold 200′, such as a capacitance,resistance, inductance or some combination thereof. The loading data 306uses the impedance measurement to indicate an amount of impregnation ofthe therapeutic material in the scaffold 200, such as via a loadingprofile, an unloading profile or other function of the impedance of thescaffold 200.

Like loading data generator 302, the loading data generator 302′ canmeasure other properties in addition to or in place of impedance. Forexample, loading data generator 302′ can include a driver and detectorcoupled to the scaffold 200′ that measure a spectral conductance,transmission or absorption of a light wave that is transmitted throughthe scaffold 200′. In a further example, loading data generator 302′ caninclude a driver and detector coupled to the scaffold 200′ that measurea spectral conductance, transmission or absorption of a millimeter waveor other RF signal transmitted through the scaffold 200′. In pertinentpart, loading data generator 302′ interacts with the scaffold 200′ viameasurements to monitor the loading and unloading of the therapeuticmaterial from the scaffold 200′. The detection circuit 314 can include aprocessor or other processing device or circuit.

In addition, loading data generator 302′ includes a loading datatransmitter 512 that communicates with the loading data 306 with thewireless loading data receiver 510. In an embodiment, the loading datatransmitter 512 and wireless loading data receiver 510 can each be partof corresponding transceivers that operate in conjunction with acommunication standard such as 802.11, Bluetooth, ZigBee,ultra-wideband, RF identification (RFID), Wimax or other standard shortor medium range communication protocol, or other protocol. In oneexample of operation, the loading data generator 302′ operates in asimilar fashion to a passive RFID tag and wireless loading data receiver510 operates as an RFID reader to provide an energy signal to power theloading data generator 302′.

In an embodiment, the loading data generator 302′ is constructed of abiodegradable circuit capable of in vivo operation in conjunction with adelivery system for tissue engineering and/or drug delivery. In anembodiment, all components of the circuit are made of biodegradablematerials. The circuit can be built upon a biodegradable substrate suchas silk, fabric, paper, caramelized glucose and/or polymers such as poly(L-lactide-co-glycolide) and thermoplastic polyesters. The circuititself can be printed onto any of these substrates using abiocompatible, conductive ink. The substrates with associated circuitsare connected via a biodegradable conductive wire, for example cottonfiber impregnated with carbon nanotubes or gold nanoparticles or abiodegradable polymer fiber doped with carbon nanotubes or goldnanoparticles. In another embodiment this wire may be composed of iron,magnesium, or alloys of the two metals, which are both conductive andbiodegradable.

In another embodiment, several individual circuits are made of abiocompatible material small enough to be eluted from the body withoutbiodegradation. For example, circuits could be printed on goldnanoparticles, which are commercially available through Sigma Aldrich.These nanoparticles would then be connected with a wire similar asdiscussed above. In either embodiment, a biodegradable battery may powerthe circuit. This battery may be single use or may be recharged viaremote methods, such as the use of radio frequency charging. This wouldallow for non-invasive charging of the battery for prolonged power tothe circuit.

FIG. 50 is a pictorial diagram of a scaffold in accordance with anembodiment of the present invention. In particular, an embodiment isshown that is similar to the scaffold delivery described in conjunctionwith FIG. 41 . In this embodiment, scaffold 200′ is delivered in placeof scaffold 230. In state 516, the loaded scaffold 200′ is delivered anddetached at the tissue site 210. In the state 518, the scaffold 200′unloads the therapeutic material at the tissue site 210 and can thenbiodegrade or otherwise remain or pass through the body without harm tothe patient.

To preserve the monitoring of loading data 306, the loading datagenerator 302′ is capable of biodegradation at slower rate than theunloading and biodegradation of the scaffold 200′. In this fashion, theloading data generator 302′ can continue to operate until the unloadingand/or biodegradation of the scaffold 200′ is completed. To achievethis, the circuit can itself be biodegradable at a slower rate or can beencapsulated in a second material such as a biodegradable plastic orfilm with a slower degradation rate than the scaffold 200′ used for thedelivery system to preserve monitoring functionality until the scaffoldsystem has adequately unloaded and/or degraded.

FIG. 51 is a graphical representation of an unloading profile inaccordance with an embodiment the present invention. In particular, anunloading profile 520 is shown as a function of concentration oftherapeutic material loaded in a scaffold, such as scaffold 200′, as afunction of time. As shown the concentration of therapeutic materialfalls as the scaffold 200′ is unloaded until an expected unloading timeE[T_(U)] is reached. On the same graph, a degradation profile 522 ispresented that represents the amount of biodegradation of the loadingdata generator 302′. In particular, the loading data generator 302′slowly degrades until a degradation threshold 524 is reached at anexpected degradation time E[T_(D)]. The degradation threshold 524 can bechosen to correspond to a point of first failure—i.e. the time where theoperation of the loading data generator 302′ would cease due tobiodegradation.

For example, the expected degradation time E[T_(D)] represents a meantime to failure of the loading data generator 302′. As shown, E[T_(D)]exceeds the value E[T_(U)] to ensure that the loading data generator302′ is still in operation at the time that unloading is expected to becomplete in order to generate loading data 306 to indicate this event.It should be noted that the loading data generator 302′ can be designedso that E[T_(D)] exceeds the value E[T_(U)] by a sufficient margin toprovide confidence that loading data generator 302′ is operatingproperly at E[T_(U)]. In an embodiment, the margin is selected toprovide a statistical confidence, such as 95% confidence, 99% confidenceor some greater or lesser confidence level that failure of the loadingdata generator 302′ does not occur before unloading of the scaffold 200′is complete.

FIG. 52 is a schematic block diagram of an embodiment of a system formonitoring a scaffold 200″ in accordance with the present invention. Inparticular, a scaffold 200″ is presented this is similar to scaffold200′ discussed in conjunction with FIGS. 48-51 except that a degradationdata generator 532, similar to loading data generator 302′ is attachedto or incorporated in the scaffold 200″ and communicates degradationdata 526 wirelessly with a wireless degradation data receiver 530. Likescaffold 200′, scaffold 200″ can be delivered via a scaffoldcatheterization device 298 that includes catheter delivery rod 150, suchas a push rod or other delivery mechanism. The degradation datagenerator 532 can be coupled to the scaffold 200″ to monitor thedegradation of the scaffold after delivery.

The wireless degradation data receiver 530 receives the degradation data526 from the degradation data generator 532. The degradation data 526can be analyzed to track a degradation profile of the scaffold andfurther can provide an indication that the scaffold is adequatelydegraded, i.e. that sufficient degradation has occurred to permit anyremaining portions of the scaffold to pass through the body or otherwiseremain without harm to the patient.

FIG. 53 is a schematic block diagram of an embodiment of a degradationdata generator in accordance with the present invention. A degradationdata generator 532 is shown that operates in a similar fashion toloading data generator 302′. In particular, degradation data generator532 includes a driving circuit 312 that, for example, is electricallycoupled to drive an impedance of the scaffold 200″. In this case, thedetection circuit 314 generates degradation data 526 based on theimpedance of the scaffold 200″, such as a capacitance, resistance,inductance or some combination thereof. The degradation data generator532 uses the impedance measurement to indicate an amount of degradationof the scaffold 200″, such as via a degradation profile, or otherfunction of the impedance of the scaffold 200″.

Like loading data generator 302′, the degradation data generator 532 canmeasure other properties in addition to or in place of impedance. Forexample, degradation data generator 532 can include a driver anddetector coupled to the scaffold 200″ that measure a spectralconductance, transmission or absorption of a light wave that istransmitted through the scaffold 200″. In a further example, degradationdata generator 532 can include a driver and detector coupled to thescaffold 200″ that measure a spectral conductance, transmission orabsorption of a millimeter wave or other RF signal transmitted throughthe scaffold 200″. In pertinent part, degradation data generator 532interacts with the scaffold 200″ via measurements to monitor thedegradation of the scaffold 200″. The detection circuit 314 can includea processor or other processing device or circuit.

In addition, degradation data generator 532 includes a degradation datatransmitter 534 that communicates with the degradation data 526 with thewireless degradation data receiver 530. In an embodiment, thedegradation data transmitter 534 and wireless degradation data receiver530 can each be part of corresponding transceivers that operate inconjunction with a communication standard such as 802.11, Bluetooth,ZigBee, ultra-wideband, RF identification (RFID), Wimax or otherstandard short or medium range communication protocol, or otherprotocol. In one example of operation, the degradation data generator532 operates in a similar fashion to a passive RFID tag and wirelessdegradation data receiver 530 operates as an RFID reader to provide anenergy signal to power the degradation data generator 532.

In an embodiment, the degradation data generator 532 is constructed of abiodegradable circuit capable of in vivo operation in conjunction with adelivery systems for tissue engineering and drug delivery. In anembodiment, all components of the circuit are made of biodegradablematerials. The circuit can be built upon a biodegradable substrate suchas silk, fabric, paper, caramelized glucose and/or polymers such aspoly(L-lactide-co-glycolide) and thermoplastic polyesters. The circuititself can be printed onto any of these substrates using abiocompatible, conductive ink. The substrates with associated circuitsare connected via a biodegradable conductive wire, for example cottonfiber impregnated with carbon nanotubes or gold nanoparticles or abiodegradable polymer fiber doped with carbon nanotubes or goldnanoparticles. In another embodiment this wire may be composed of iron,magnesium, or alloys of the two metals, which are both conductive andbiodegradable.

In another embodiment, several individual circuits are made of abiocompatible material small enough to be eluted from the body withoutbiodegradation. For example, circuits could be printed on goldnanoparticles, which are commercially available through Sigma Aldrich.These nanoparticles would then be connected with a wire similar asdiscussed above. In either embodiment, a biodegradable battery may powerthe circuit. This battery may be single use or may be recharged viaremote methods, such as the use of radio frequency charging. This wouldallow for non-invasive charging of the battery for prolonged power tothe circuit.

FIG. 54 is a pictorial diagram of a scaffold in accordance with anembodiment of the present invention. In particular, an embodiment isshown that is similar to the scaffold delivery described in conjunctionwith FIG. 41 . In this embodiment, scaffold 200″ is delivered in placeof scaffold 230. In state 550, the loaded scaffold 200″ is delivered anddetached at the tissue site 210. In the state 544, the scaffold 200″unloads the therapeutic material at the tissue site 210 and further, hasbiodegraded.

To preserve the monitoring of degradation data 306, the degradation datagenerator 532 is capable of biodegradation at slower rate than theunloading and biodegradation of the scaffold 200″. In this fashion, thedegradation data generator 532 can continue to operate until theunloading and biodegradation of the scaffold 200″ is completed. Toachieve this, the circuit can itself be biodegradable at a slower rateor can be encapsulated in a second material with a slower degradationrate than the scaffold 200″ used for the delivery system to preservemonitoring functionality until the scaffold system has adequatelyunloaded and/or degraded.

FIG. 55 is a graphical representation of a degradation profile inaccordance with an embodiment the present invention. In particular, adegradation profile 542 is shown for a scaffold, such as scaffold 200″,as a function of time. As shown, the scaffold 200″ slowly degrades untila degradation threshold 524 is reached at an expected degradation timeE[T_(D1)]. The degradation threshold is chosen to correspond to a pointwhere the operation of the scaffold 200′ is sufficiently degraded toallow the remaining portions of the scaffold 200′ to pass through thebody of the patient or remain without harm. On the same graph, adegradation profile 544 is presented that represents the amount ofbiodegradation of the degradation data generator 532. In particular, thedegradation data generator 532 slowly degrades until a degradationthreshold 524 is reached at an expected degradation time E[T_(D1)]. Thedegradation threshold 524 is chosen to correspond to a point where theoperation of the degradation data generator 532 would cease due tobiodegradation. While the same degradation threshold 524 is shown forboth the degradation data generator 532 and the scaffold 200″, differentdegradation thresholds can be used. In an embodiment, while thedegradation threshold for the degradation data generator 532 is chosento represent first failure, a lower degradation threshold for thescaffold 200″ can be used to represented that the scaffold hassubstantially degraded, i.e. that sufficient degradation has occurred toallow the remaining portions of the scaffold 200′ to pass through thebody of the patient or remain without harm.

For example, the expected degradation time E[T_(D2)] represents a meantime to failure of the degradation data generator 532. As shown,E[T_(D2)] exceeds the value E[T_(D1)] to ensure that the degradationdata generator 532 is still in operation at the time that degradation ofscaffold 200″ is expected to be complete in order to generatedegradation data 526 to indicate this event. It should be noted that thedegradation data generator 532 can be designed so that E[T_(D2)] exceedsthe value E[T_(D1)] by a sufficient margin to provide confidence thatdegradation data generator 532 is operating properly at E[T_(D1)]. In anembodiment, the margin is selected to provide a statistical confidence,such as 95% confidence, 99% confidence or some greater or lesserconfidence level that failure of the degradation data generator 532 doesnot occur before degradation of the scaffold 200″ is complete.

FIG. 56 is a flowchart representation of an embodiment of a method inaccordance with the present invention. In particular a method ispresented for use in conjunction with one or more functions and featurespresented in conjunction with FIGS. 1-55 . Step 600 includesendovascular insertion of a biodegradable scaffold via a catheter,wherein the scaffold is impregnated with a therapeutic material. Step602 includes electrically driving a circuit that includes an impedanceof the scaffold via a biodegradable driving circuit. Step 604 includesgenerating loading data based on the impedance of the scaffold via abiodegradable detection circuit, wherein the loading data indicatesunloading of the therapeutic material from the scaffold. Step 606includes wirelessly transmitting the loading data to a wireless loadingdata receiver via a biodegradable wireless transmitter of the scaffold.

FIG. 57 is a flowchart representation of an embodiment of a method inaccordance with the present invention. In particular a method ispresented for use in conjunction with one or more functions and featurespresented in conjunction with FIGS. 1-56 . Step 610 includesendovascular insertion of a biodegradable scaffold via a catheter,wherein the scaffold is impregnated with a therapeutic material. Step612 includes driving the scaffold via a biodegradable driving circuitthat generates an RF signal or lightwave. Step 614 includes generatingloading via a biodegradable detection circuit of the scaffold, whereinthe loading data indicates unloading of the therapeutic material fromthe scaffold. Step 616 includes wirelessly transmitting the loading datato a wireless loading data receiver via a biodegradable wirelesstransmitter of the scaffold.

FIG. 58 is a flowchart representation of an embodiment of a method inaccordance with the present invention. In particular a method ispresented for use in conjunction with one or more functions and featurespresented in conjunction with FIGS. 1-57 . Step 620 includesendovascular insertion of a biodegradable scaffold via a catheter. Step622 includes electrically driving a circuit that includes an impedanceof the scaffold via a biodegradable driving circuit. Step 624 includesgenerating degradation data based on the impedance of the scaffold via abiodegradable detection circuit, wherein the degradation data indicatesbiodegradation of the scaffold. Step 626 includes wirelesslytransmitting the degradation data to a wireless loading data receivervia a biodegradable wireless transmitter of the scaffold.

FIG. 59 is a flowchart representation of an embodiment of a method inaccordance with the present invention. In particular a method ispresented for use in conjunction with one or more functions and featurespresented in conjunction with FIGS. 1-58 . Step 630 includesendovascular insertion of a biodegradable scaffold via a catheter. Step632 includes driving the scaffold via a biodegradable driving circuitthat generates an RF signal or lightwave. Step 634 includes generatingdegradation data via a biodegradable detection circuit of the scaffold,wherein the degradation data indicates biodegradation of the scaffold.Step 636 includes wirelessly transmitting the degradation data to awireless loading data receiver via a biodegradable wireless transmitterof the scaffold.

While the foregoing description has focused on heat induced shape memorytransformation, transformation can be actuated via other stimuli. Forexample, shape transformations can be actuated via exposure to liquidssuch as water or other chemicals, by solution pH, solvent composition,electrical and magnetic fields, sonic or ultrasonic waves, ultraviolet,visible or other light or other actuation modes. The various embodimentsdescribed herein can be modified to any of these additional shape memorytransformation modes. In these cases, the various temperature thresholdscorresponding to the state transitions of a shape memory element areimplemented instead by stimulation thresholds corresponding to theparticular transformation stimulus or stimuli employed. Further, while asingle stimulus has been discussed for implementing the transitionbetween the various states of a shape memory element, multiple differentstimuli can be employed.

As may be used herein, the terms “substantially” and “adequately”provides an industry-accepted tolerance for its corresponding termand/or relativity between items. Such an industry-accepted toleranceranges from less than one percent to fifty percent and corresponds to,but is not limited to, component values, integrated circuit processvariations, temperature variations, rise and fall times, and/or thermalnoise. Such relativity between items ranges from a difference of a fewpercent to magnitude differences. As may also be used herein, theterm(s) “configured to”, “operably coupled to”, “coupled to”, and/or“coupling” includes direct coupling between items and/or indirectcoupling between items via an intervening item (e.g., an item includes,but is not limited to, a component, an element, a circuit, and/or amodule) where, for an example of indirect coupling, the intervening itemdoes not modify the information of a signal but may adjust its currentlevel, voltage level, and/or power level. As may further be used herein,inferred coupling (i.e., where one element is coupled to another elementby inference) includes direct and indirect coupling between two items inthe same manner as “coupled to”. As may even further be used herein, theterm “configured to”, “operable to”, “coupled to”, or “operably coupledto” indicates that an item includes one or more of power connections,input(s), output(s), etc., to perform, when activated, one or more itscorresponding functions and may further include inferred coupling to oneor more other items. As may still further be used herein, the term“associated with”, includes direct and/or indirect coupling of separateitems and/or one item being embedded within another item.

As may be used herein, the term “compares favorably”, indicates that acomparison between two or more items, signals, etc., provides a desiredrelationship. For example, when the desired relationship is that signal1 has a greater magnitude than signal 2, a favorable comparison may beachieved when the magnitude of signal 1 is greater than that of signal 2or when the magnitude of signal 2 is less than that of signal 1.

As may also be used herein, the terms “processing module”, “processingcircuit”, “processor”, and/or “processing unit” may be a singleprocessing device or a plurality of processing devices. Such aprocessing device may be a microprocessor, micro-controller, digitalsignal processor, microcomputer, central processing unit, fieldprogrammable gate array, programmable logic device, state machine, logiccircuitry, analog circuitry, digital circuitry, and/or any device thatmanipulates signals (analog and/or digital) based on hard coding of thecircuitry and/or operational instructions. The processing module,module, processing circuit, and/or processing unit may be, or furtherinclude, memory and/or an integrated memory element, which may be asingle memory device, a plurality of memory devices, and/or embeddedcircuitry of another processing module, module, processing circuit,and/or processing unit. Such a memory device may be a read-only memory,random access memory, volatile memory, non-volatile memory, staticmemory, dynamic memory, flash memory, cache memory, and/or any devicethat stores digital information. Note that if the processing module,module, processing circuit, and/or processing unit includes more thanone processing device, the processing devices may be centrally located(e.g., directly coupled together via a wired and/or wireless busstructure) or may be distributedly located (e.g., cloud computing viaindirect coupling via a local area network and/or a wide area network).Further note that if the processing module, module, processing circuit,and/or processing unit implements one or more of its functions via astate machine, analog circuitry, digital circuitry, and/or logiccircuitry, the memory and/or memory element storing the correspondingoperational instructions may be embedded within, or external to, thecircuitry comprising the state machine, analog circuitry, digitalcircuitry, and/or logic circuitry. Still further note that, the memoryelement may store, and the processing module, module, processingcircuit, and/or processing unit executes, hard coded and/or operationalinstructions corresponding to at least some of the steps and/orfunctions illustrated in one or more of the Figures. Such a memorydevice or memory element can be included in an article of manufacture.

One or more embodiments of an invention have been described above withthe aid of method steps illustrating the performance of specifiedfunctions and relationships thereof. The boundaries and sequence ofthese functional building blocks and method steps have been arbitrarilydefined herein for convenience of description. Alternate boundaries andsequences can be defined so long as the specified functions andrelationships are appropriately performed. Any such alternate boundariesor sequences are thus within the scope and spirit of the claims.Further, the boundaries of these functional building blocks have beenarbitrarily defined for convenience of description. Alternate boundariescould be defined as long as the certain significant functions areappropriately performed. Similarly, flow diagram blocks may also havebeen arbitrarily defined herein to illustrate certain significantfunctionality. To the extent used, the flow diagram block boundaries andsequence could have been defined otherwise and still perform the certainsignificant functionality. Such alternate definitions of both functionalbuilding blocks and flow diagram blocks and sequences are thus withinthe scope and spirit of the claimed invention. One of average skill inthe art will also recognize that the functional building blocks, andother illustrative blocks, modules and components herein, can beimplemented as illustrated or by discrete components, applicationspecific integrated circuits, processors executing appropriate softwareand the like or any combination thereof.

The one or more embodiments are used herein to illustrate one or moreaspects, one or more features, one or more concepts, and/or one or moreexamples of the invention. A physical embodiment of an apparatus, anarticle of manufacture, a machine, and/or of a process may include oneor more of the aspects, features, concepts, examples, etc. describedwith reference to one or more of the embodiments discussed herein.Further, from figure to figure, the embodiments may incorporate the sameor similarly named functions, steps, modules, etc. that may use the sameor different reference numbers and, as such, the functions, steps,modules, etc. may be the same or similar functions, steps, modules, etc.or different ones.

Unless specifically stated to the contra, signals to, from, and/orbetween elements in a figure of any of the figures presented herein maybe analog or digital, continuous time or discrete time, and single-endedor differential. For instance, if a signal path is shown as asingle-ended path, it also represents a differential signal path.Similarly, if a signal path is shown as a differential path, it alsorepresents a single-ended signal path. While one or more particulararchitectures are described herein, other architectures can likewise beimplemented that use one or more data buses not expressly shown, directconnectivity between elements, and/or indirect coupling between otherelements as recognized by one of average skill in the art.

The term “module” is used in the description of one or more of theembodiments. A module includes a processing module, a processor, afunctional block, hardware, and/or memory that stores operationalinstructions for performing one or more functions as may be describedherein. Note that, if the module is implemented via hardware, thehardware may operate independently and/or in conjunction with softwareand/or firmware. As also used herein, a module may contain one or moresub-modules, each of which may be one or more modules.

While particular combinations of various functions and features of theone or more embodiments have been expressly described herein, othercombinations of these features and functions are likewise possible. Thepresent disclosure of an invention is not limited by the particularexamples disclosed herein and expressly incorporates these othercombinations.

What is claimed is:
 1. A loading data generator comprising: a drivingcircuit electrically coupled to drive an impedance of a scaffold fordelivery within a patient, wherein the scaffold is coupled to a deliveryrod for the delivery in the patient via catheterization and wherein thedriving circuit is coupled to the scaffold via a plurality ofelectrodes; a detection circuit, coupled to the driving circuit forgenerating loading data based on the impedance of the scaffold, whereinthe loading data indicates an amount of impregnation of therapeuticmaterial in the scaffold and wherein the loading data indicates aloading measurement prior to the catheterization; and a wirelesstransmitter, coupled to transmit the loading data to a wireless loadingdata receiver.
 2. The loading data generator of claim 1 wherein theloading data provides an indication when impregnation of the therapeuticmaterial in the scaffold is complete, prior to the catheterization. 3.The loading data generator of claim 1 wherein the loading data isgenerated based on an impedance measurement prior to thecatheterization.
 4. The loading data generator of claim 1 wherein theloading data indicates, based on a first impedance measurement, a firstloading measurement when the scaffold is delivered in the patient. 5.The loading data generator of claim 4 wherein the loading dataindicates, based on a second impedance measurement, a second loadingmeasurement when the scaffold is delivered in the patient, wherein thesecond loading measurement indicates the therapeutic material isunloaded from the scaffold.
 6. The loading data generator of claim 1wherein the detection circuit measures a capacitance of the scaffold. 7.The loading data generator of claim 1 wherein the detection circuitmonitors a loading profile of the scaffold.
 8. A method comprising:driving, via a driving circuit, an impedance of a scaffold for deliverywithin a patient, wherein the scaffold is coupled to a delivery rod forthe delivery in the patient via catheterization and wherein the drivingcircuit is coupled to the scaffold via a plurality of electrodes;generating, via a detection circuit coupled to the driving circuit,loading data based on the impedance of the scaffold, wherein the loadingdata indicates an amount of impregnation of therapeutic material in thescaffold and wherein the loading data indicates a loading measurementprior to the catheterization; and wirelessly transmitting the loadingdata to a wireless loading data receiver.
 9. The method of claim 8wherein the loading data provides an indication when impregnation of thetherapeutic material in the scaffold is complete, prior to thecatheterization.
 10. The method of claim 8 wherein the loading data isgenerated based on an impedance measurement prior to thecatheterization.
 11. The method of claim 8 wherein the loading dataindicates, based on a first impedance measurement, a first loadingmeasurement when the scaffold is delivered in the patient.
 12. Themethod of claim 11 wherein the loading data indicates, based on a secondimpedance measurement, a second loading measurement when the scaffold isdelivered in the patient, wherein the second loading measurementindicates the therapeutic material is unloaded from the scaffold. 13.The method of claim 8 wherein the detection circuit measures acapacitance of the scaffold.
 14. The method of claim 8 wherein thedetection circuit monitors a loading profile of the scaffold.
 15. Adevice comprising: a scaffold: a delivery rod; a driving circuitelectrically coupled to drive an impedance of the scaffold for deliverywithin a patient, wherein the scaffold is coupled to the delivery rodfor the delivery in the patient via catheterization and wherein thedriving circuit is coupled to the scaffold via a plurality ofelectrodes; a detection circuit, coupled to the driving circuit forgenerating loading data based on the impedance of the scaffold, whereinthe loading data indicates an amount of impregnation of therapeuticmaterial in the scaffold and wherein the loading data indicates aloading measurement prior to the catheterization; and a wirelesstransmitter, coupled to transmit the loading data to a wireless loadingdata receiver.
 16. The device of claim 15 wherein the loading dataprovides an indication when impregnation of the therapeutic material inthe scaffold is complete, prior to the catheterization.
 17. The deviceof claim 15 wherein the loading data is generated based on an impedancemeasurement prior to the catheterization.
 18. The device of claim 15wherein the loading data indicates, based on a first impedancemeasurement, a first loading measurement when the scaffold is deliveredin the patient.
 19. The device of claim 18 wherein the loading dataindicates, based on a second impedance measurement, a second loadingmeasurement when the scaffold is delivered in the patient, wherein thesecond loading measurement indicates the therapeutic material isunloaded from the scaffold.
 20. The device of claim 15 wherein thedetection circuit monitors a loading profile of the scaffold.